I recently finished reading "The Forest For the Trees: And Editor's Advice To Writers". by Betsy Lerner.
I'd give it an 8 out of 10, purely for entertainment reasons. Lerner is a fine writer, and this was an enjoyable read. She tells stories on a lot of writers she has worked with, but without mentioning their names so we get to enjoy their foibles without that sense of reading a book full of gossip. She also tells a few stories on herself and clearly doesn't want us to think that she is above the temptations toward idiocy that every writer experiences. In fact, I'd love it if she would be my editor, and if she would find me an agent (Betsy, if you're reading this, email me).
What I had hoped for was more practical advice: how to start on the road to getting an agent (who do I call or write to or see?), how might I start putting together a portfolio, if I have a few publication credits and no formal training what should I do next, stuff like that. These things were, I think, beyond the scope of the book but I'm sure she could have included them. With her skills, I'm sure she would still have produced a wonderfully compelling book.