True Aim makes a very good point; the best books on writing are the books by writers you admire and whose success you wish to emulate. If you are writing genre, study the successful writers in that genre. For example, if you are writing detective fiction, you should read Raymond Chandler, Dashiell Hammett, Lawrence Block, Laura Lippman, John Sandford, etc. You should also read the so-called greats for how they attack the craft of writing- i.e., Dickens on characterization, Hemingway on narrative, etc. Good writers are well read.
If you are looking for a guidebook, you can't do much better than Lawrence Block's "Writing the Novel: From Plot to Print ". Block is one of the most successful popular writers today, and this is a good selection of tips and advice he's learned over the years.
You might also try Writer's Digest Magazine. The Pros actually use it.