I've read his newest book, "Meditating Selflessly: Practical Neural Zen", that seems to be aimed more at a layperson than "Zen and the Brain". It also talks a bit about his speculations about what meditation does in the brain, along with some recommendations on meditation. It might be too speculative though.

He also has a third book, perhaps that is a happy medium? Depending on how motivated you are, you might even try one of those Human Brain coloring books...