I like "The Cake Bible" a lot, and contrary to what other people have said here and in other venues, I find I can change Rose Levy Beranbaum's reicpes and use rice milk instead of milk and shortening and water instead of butter and an occassional whole egg instead of two yolks and so on. Especially once you've read/studied the "Understanding" sections of the book, you'll know why things work as they do and what you can get away with changing.
The fact that she gives measurements by weight as well as volume I find extremely helpful becasue I'd much rather weigh my ingredients.
I find Beranbaum's basic chocolate cake recipe to be pretty dry--and even people who haven't changed a thing have said this, but I just had a taste test last night between her basic yellow cake which I had changed to a non-dairy fornula and another yellow cake from a non-dairy book, and The Cake Bible yellow cake won almost across the board for texture and got a lot of "best taste" votes too. (There were 8 pepole tasting the 2 cakes without icing or filling)
There are tables in the back of the book which detail how much icing for different sizes of cakes, and there is a system for how much batter to make if you use her basic reicpes in various sizes of pans. There are also extended instructions for various wedding cakes to serve 150 or more.
Definitely a useful book.