The only dedicated vegan baking book I know of is the Joy Of Vegan Baking, but Colleen Patrick Goudreau. It's a good basic book, but honestly, nothing in it really wowed me. If you're just starting out in vegan baking, I think it would be a good resource, though, for sure.

Other than that, I am a fan of Isa Chandra Moskowitz and Terry Romero's books. They have put out a vegan cupcake book that is killer and are releasing a vegan cookie book in the next few months. They've also written The Veganomicon, which is a great all-purpose cookbook with some really killer baking recipes.

Finally, a friend of mine has a really great website (and zine) that is not exclusively about vegan baking but has a great section on vegan cakes and also some awesome cookie and bar recipes: www.pakupaku.info