http://www.animatedknots.com/indexfishing.php
If you only knew one knot for fishing, this might be a good one. It has good strength, is easy to rig on a kayak, and can be used for any hook or lure that doesn't require a loop for proper swimming action.
http://www.raley.com/knots/cinch-1.gif
First, pass the bitter end of the line thru the eyelet of the hook or lure
http://web.archive.org/web/20070528120528/http://www.raley.com/knots/cinch-2.gif
Next, make a loop back to the rest of the line
http://web.archive.org/web/20070528120528/http://www.raley.com/knots/cinch-3.gif
Wrap the bitter end of the line around at least 4 times
http://www.raley.com/knots/cinch-4.gif
Thread the bitter end back thru the loop you originally created
http://www.raley.com/knots/cinch-5.gif
Pull the bitter end tight. Test the knot by pulling (less than the breaking strength!) Trim closely.