I think the most important tools for going veg*n are the cookbooks, so which ones do you just love?
Mine are (in no real order):
Anything by Isa Chandra Moskowitz, but especially Vegan With a Vengeance (I'm currently reading The Veganomicon and Vegan Brunch; so far, excellent!),
The Clueless Vegetarian by Evelyn Raab,
1,000 Vegetarian Recipes by Carol Gelles (and she ain't kidding, either