I would figure that the booksmarts skill which is already based around large amounts of Alchemical knowledge, would count for that. If anything, that's the skill I'll be switching over to it. 

As for the book, yeah it's not like a precise 'here's how you do human transmutaiton', it's more just, the thoughts on it, what people have tried, at least what was recorded and tried, and the makeup of the human body. It's not actually instructions on how to do it.