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.