I shamelessly stole this site from GYC. Who uses which knot for what? 
http://www.animatedknots.com/indexb...
Pete:
Nice link. I bookmarked it. I use and swear by a bowline all over boat and trailer. You can ALWAYS get it loose no matter how tight it get. I also use a figure 8 on the end of my main sheet as it becomes my traveler line and tie to a loop on the rear crossbar.
Doug Snell
Hobie 17
Soon to be Mystere 4.3
www.tcdyc.com
bowline bowline bowline...
still can't figure out a square knot half the time
The next question to ask is how to tie a bowline- there have to be a hundred ways
Great site Pete 
Personally I use the bowline and figure 8.
But growing up around my fathers boats I've learned how to use a lot of those knots at a young age. I would always get yelled at because I was always the first one jumping off the boat and on to the dock to tie the ropes even before the boat came to a stop.
I use the Cleat hitch a lot on his larger boats, as well as the anchor bend and fishermans bend.
Though I must admit that I didnt know what they were called in english till I saw this post.
Guys:
Friend taught me a funny little saying for the bowline. Flip the loop upwards. Take the end of the rope. The rabbit goes out of the hole around the tree and back through the hole. You will never forget how to tie a bowline.
Doug Snell
Hobie 17
Soon to be Mystere 4.3
www.tcdyc.com
Personally I use the bowline and figure 8.
But growing up around my fathers boats I've learned how to use a lot of those knots at a young age. I would always get yelled at because I was always the first one jumping off the boat and on to the dock to tie the ropes even before the boat came to a stop.
I use the Cleat hitch a lot on his larger boats, as well as the anchor bend and fishermans bend.
Though I must admit that I didnt know what they were called in english till I saw this post.
Zee; I'll bet you're the only person on this forum that can tie all those knots. My knots are mostly nots! 
LOL pete I bet there are loads of people here who know a lot more about knots than I do
I'll take that bet! For the majority of cat sailors, it's the square knot and bowline!
What shall we wager, more importantly, how will the winner collect?
still can't figure out a square knot half the time
The next question to ask is how to tie a bowline- there have to be a hundred ways
PTP - the way I remembered the square knot was "Left over right , right over left" (or visa versa)
Try it - it makes it easy.
As for the bowline - well that's just practice. 
I use cleat hitch, clove hitch, double half-hitch, trucker's hitch, and BOWLINE.
Bowline is the most important. I never could figure out the rabbit-and-hole technique. I have a super-fast way to tie a bowline, and I can do it right-handed, left-handed and blindfolded. But I don't know how to describe what I do. It's just flop, twist, flip, flip, pull.
Carlton Tucker claimed he could tie the fastest bowline, but I beat him (just barely). 
Here's another good knot site.
Real Knots
How trustworty do y'all find the cow hitch for attaching the short length of line with the clew blocks to the jib clew? It seems like that's what everyone uses, but to me, it looks like it could slip.
I must admit that I used to know a lot more knots than I do now, but bungee cords and tie-down straps with splice on hooks make knots like the tautline hitch and lineman's loop obsolete.
But my rabbit is dyslexic (and can't spell either). I found just tying the knot over and over you finally get it right. The bowline is real handy for most situations if you need to get it undone easily. A hand full of knots can get you through most situations. Square knot, right over left, left over right does it. If you do it wrong it becomes a granny knot...
Clayton
Mary: Carlton was at our 20th Madcatter and he and Walley Meyers had a bowline competition. They were given about a 3" inch diam rope and told they had to tie it behind their backs.
I don't remember who won but it was a lot of fun.
For people that didn't know Carlton they should go read Mary's write up in the Hall of Fame. He was an amazing guy.
I was introduced to him at the 93 Nationals in New Jersey. He had his old 84 boat he picked up just prior to the event. He offered to look at my boat setup. He said: Bub it looks like it's setup like everyone else so just go out and beat them. He went on to finish 4th and I got a "trophey" for 75th. Were do you hang that up?
Mary,
You might want to consider substituting the rolling hitch for the clove hitch. It's basically just a clove with one more loop under the overlapping piece, but it's more secure.
The thing's you remember from Boy Scouts.
Rolling hitch-Great for clearing overlayed winches.
Not that it's ever happened to me 
Tommy, aren't you the one that says: "If you can't tie a good not, tie lots of em."
Usually after watching my catsailing buds try and tie a dock line 
Bowline is the most important. I never could figure out the rabbit-and-hole technique. I have a super-fast way to tie a bowline, and I can do it right-handed, left-handed and blindfolded. But I don't know how to describe what I do. It's just flop, twist, flip, flip, pull.
Carlton Tucker claimed he could tie the fastest bowline, but I beat him (just barely).
I've seen the superfast bowline, it is almost literally a flick of the wrist!! It drives me crazy that I can't do it! 
So far, it's only the ladies that have a knot repertoire.
Some jokers once showed me the worlds fastest way to tie a bowline. They used both hands and their arms. They through a loop into the rope while holding the rope at each end of the knot. Then fliped it a couple of times and drew the ends tight. Bingo! A dragon bowline. "Dragon?" I said.
They would respond, "Yeah, draggin'. Cause all it is good for is dragging on the ground behind you."
The point of the joke was that this method of tying the bowline was only good for a loop on the end of a line (to be dragged behind). Because this style of tying the knot could not be implimented if you were actually tying, attaching the rope to something.
I tie a bowline differently than about 95% of everyone else. I start with a slip knot (slippery half hitch) with the standing part of the line as the slipping loop. This slippery half hitch is kept loose and is not cinched. Then the bitter end of the line is passed through the sliding loop. Then the bitter end is bent through the middle of the slippery half hitch by tightening up the slippery half hitch and thus inverting the knot.
The loop in what used to be the slipery half hitch is drawn through the loop, pulling the folded bitter end with it.
Maybe I'll shoot a mpeg of this.
GARY
They would respond, "Yeah, draggin'. Cause all it is good for is dragging on the ground behind you."
The point of the joke was that this method of tying the bowline was only good for a loop on the end of a line (to be dragged behind). Because this style of tying the knot could not be implimented if you were actually tying, attaching the rope to something.
Gary, that's not how I do it. I make a regular bowline knot, big loop or small loop or whatever. I've never seen the dragon bowline, but sounds like a good stunt, even if it isn't good for anything.
Pat, since you mentioned tying it behind the back, I had to try it. First time, 3 seconds flat. Tying a bowline is the only thing I do well. Had to get lots of practice at it when we were sailing our cruising boat many years ago. Seems like a lot more knots are used (and used more often) on a big boat than on a beach cat.
A necessary knot for the Tornado type main halyard hook-and-ring is to use the Bunline Hitch on that ring. It's compact, strong, and easy to tie (if not always easy to untie, but I've never had a problem). Many use a bowline up there on that ring but it's bulky and gets in the way of the hooking and unhooking.
What a great site. I have a friend who can tie a one-handed bowline simultniously with one in each hand. Very clever though I don't know what purpose it serves. I've watched him to it several times and have never been able to figure it out - until now.
Steve, you have me worried now. No way can I do it with one hand.
My brother, when he was a boyscout, showed me the one-handed bowline. It is very cute how it works and it does work. I do use it still, as it is actually the easiest way to tie one.
Mary I think Pat said you had to use a 3 inch [color]diameter line behind your back. Is that what you used?
I spent a few summers on replica wooden sailboats from the War of 1812 (about the time Master and Commander is based on). you learn all kinds of knots working on period vessels. The ones I use(d) the most are Bowline, clove hitch, & taughtline hitch. Being able to "throw" a clove hitch over a post is a good skill to have when dealing with dock lines.
I also learned why sailors tend to be very good with knots. On some of my longer trips there wasn't much to do if you were not on watch so you practiced your knots and learned totally useless knots to pass the time.
For those of you who, like me, enjoy learning about knots pick up a copy of "The Marlinspike Sailor" by Smith. One of the best maritime knot books I have seen.
Nick, does Smith's book get into splicing braided line? Has anyone here mastered eye splices in braid? I have Ashley's, but it pre-dates braided line.
But my rabbit is dyslexic (and can't spell either). I found just tying the knot over and over you finally get it right. The bowline is real handy for most situations if you need to get it undone easily. A hand full of knots can get you through most situations. Square knot, right over left, left over right does it. If you do it wrong it becomes a granny knot...
Clayton
Lots of memories from Boy Scouts as a patrol leader trying to teach the other guys how to tie a bowline. I use the rabbit method, but for some reason some people get so into the rabbit and hole and such that they just can't picture the mechanics of the knot. Very funny times seeing people repeatedly reciting "the rabbit comes out of the hole..." only to end up with nothing useful and starting over again.
I tried to show a powerboat friend how to tie one as I was helping him prepare his boat for Isabel. He never did tie one on his own, but I still hear jokes about the rabbit coming out of the hole and then heading for the bar.
As for knots I use - figure eight, bowline, two half hitches, clove hitch, cleat hitch, square knot, taut line hitch, will add the midshipmen's tautline hitch to a clove hitch when tying a dockline to a piling in a more permanent fashion. I use two half hitches a lot for places that require a compact knot. I can do the splicing for three-strand ropes, have yet to figure out the modern braided ones...
I used to swear by bungees for securing and wrapping things up, but have become very wary of them - you only have to have the end of one slip out of your hand while wrapping it around something to have a severe eye injury from the flying end hook. Velcro straps and plastic wires ties are much better...
Brian Toss's book The Rigger's Apprentice is a good one for a whole variety of stuff.
I think it does discuss braided line. I don't remember in how much detail as I do most of my splicing on "old fashioned" line. Just make sure you get the newer edition as I know the original does not cover braided line.
I also like that the book goes into how rope is made and the history of the knots. There are also plenty of decorative knots and other novelties like rope fenders.
Steve,
I checked the book and it does cover in detail braided line splices.
A necessary knot for the Tornado type main halyard hook-and-ring is to use the Bunline Hitch on that ring.
Dean,
Thanks for posting the link. It's been ten years since I needed to use the buntline and I couldn't remember how to tie it. It works great on trap handles too.