I don't recommend writing books lightly, mainly b/c I own too many crappy ones. (There's a few writers here, which is why I'm posting this.) But while fooling around on SFWA's web site, I saw that one of their writers recommended Ken Rand's The 10% Solution. This is the absolute BEST book I have ever read concerning editing. About the first half of it is just prattle, imo, but after that, it's distilled wisdom. It's all the things us writers know we should be doing, but it helps to pull out those flabby adjectives/adverbs...and basically helps a writer to use his or her verbal muscles.
For those who don't know, This Dark Magic is going to be released in a horror anthology tentatively entitled Playing with Fire. So I'm using The 10% Solution to tighten it up even more so it will be a revised edition. For anyone not keeping up...I'm writing a novel, revising a shortie novella, helping with editing on the collection, and doing cover art for the collection. The cover art was done with the help of Obsidian Dawn's brushes. http://www.obsidiandawn.com/ and once I work out a couple bugs and make sure the other writers like it, I'll post it here and keep everyone updated.
For anyone else not interested in paying so stinking much for Rand's book on Amazon, I found a digital edition here: http://www.fictionwise.com/ebooks/b19307/The-10-Solution/Ken-Rand/?si=0 for $1.59
I bought the PDF and even though you can't print, you can copy/paste and print. I'm excited by how much it's helping me improve.