I already had LaBerge's Exploring the world of Lucid Dreaming, and his other one which I think is just called Lucid Dreaming.

I got these three:

The Lucid Dreamer - Malcolm Godwin
The Lucid Dreaming Kit - Paul Devereux and Charla Devereux
Creative Dreaming - Patricia Garfield

At leats 2 of those are pretty old (published in early 90s/80s I'd say...) The lucid dreaming kit comes with a cassette and some 'lucid dreaming oil.' I haven't tried the oil yet, or looked into exactly what the main ingredient's properties are, but my first impression was that it was a load of phooey.

I haven't started reading any of them yet; I want to finish my current book first. When I read them, I'll keep you all updated on how good they are, and how useful I find them.