If you can avoid getting lost in the belief system, Robert Bruce has some excellent books. Don't be afraid just because he has a more new-agey way of looking at things. The exercises he describes are very useful. I'm currently working through his 90 day program again. Viewed from a lucid dreaming perspective, the meditations are hugely helpful. He has great meditations to learn to direct your awareness, relax your body, silence your internal dialogue, and improve dream recall. If you have some experience with WILD, you can immediately see where his OBE separation tricks apply.