Ruby: A quick check at Amazon shows no newer edition to the Valerie Kelly book.

As for what I've found useful, I think the more you can read, period, the better. I read nearly anything I can get my hands on and have for as long as I can remember. It helps.

Jane Smiley has a new book out that I'm anxious to get, "Thirteen Ways of Looking at the Novel". She has taught writing as well as being a successful writer.

I've found the required reading Ruby has for Level Three students in the Writer's Block to be quite useful. Much of it is found at Literotica.com.