Hey G,
It's not like you have to learn a ton of knots. About the only knot that is used is a Sheet Bend. There is a book that I used to teach myself how to net. It's: Netmaking, Charles Holdgate, Emerson Books Inc., 1972, SBN# 87523-180-2. I originally got it from the library and photocopied it. Quite often it's offered in used on-line bookstores for about $10.00.
It was originally written to teach teachers how to teach school children (I guess that's why I was successful

). It starts out teaching how to tie the basic knot and then you work through a series of ever more difficult (not that they are) projects, each of which teaches you one or more new techniques. There are other ones available too.
These are the books I have:
Netmaking, Charles Holdgate, Emerson Books Inc., 1972, SBN# 87523-180-2 (highly recommended)
Down East Netting, Barbara M. Morton, Pea Soup Publishing, 1988, ISBN#
0-9728496-0-2 (an interesting book and it would also do the trick)
Make Nets Here's How, H.T. Ludgate,
Jann's Netcraft, 1976. (very inexpensive book and available from Jann's Netcraft) I used this book to make my Snapping Turtle trap.
Mat and Basket Weaving of the Ancient Hawaiians, William T. Brigham, Bishop Museum Press, 1906, N/A (historical and specialized - free download, not recommended for beginners)
Netmaking, P. W. Blandford, Brown, Son, & Ferguson, 1986, ISBN# 0 85174 491 5 (just got it a little while ago on the recommendation of asemery - haven't had a chance to check it out much yet)
A Text-Book of Netting and Net Making, Blackfriars Press, (orig.) 1948,
ISBN# 978-1-40679-871-5 (also a recent acquisition - also have had no chance to check it out)
How To Make & Mend Cast Nets, Ted Dahlem, Great Outdoors Publishing, 2000, ISBN# 0-8200-0612-2 (specialized for making cast nets - not recommended for beginning net makers)
Good Luck,
Doc