There are many wonderful references on Tunisian crochet on the web. Here are some of my favourites:
Books
The Harmony Guide - 300 Crochet Stitches
The Harmony Guide - 220 More Crochet Stitches
The Ultimate Sourcebook of Knitting and Crochet Stitches
Websites
Crochet Cabana - basic tutorial on stitches
Tunisian Crochet Group - a Yahoo group that I moderate
Chez Crochet - tutorials on more intricate stitches
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