tying knots

spent way fu*&#$@ too much time last night trying to tie a blood know with
which to secure some new tippet to my leader, so i went in to see the nice
folks at appalachian angler today, to see if they might be of assistance.
the nice young man behind the counter spent about half an hour showing me a
couple of different knots. we practiced with some threads, and then when he
thought i might have the hang of it, he let me do the job with a double
surgeon's knot. I'm pretty sure that was the name of it. anyway, he showed
me a couple of other knots, including a nail knot. i just hope i can
remember how to do them again when the time comes. he also tipped me off on
how long my leader should be and how long my tippet should be, and showed me
a nifty double loop kind of thing that allows changing leader with quite so
much fuss. this knot tying stuff is not easy. he did show me a neat little
knot tying tool. any recommendations for favorites?

snakefiddler