The books I bought, from Amazon.co.uk, are The Complete Idiot's Guide to Zen Living by Gail Carr and Lisa Lenard, and The Complete Idiot's Guide to Understanding Buddhism by Gary Gach.
I'm about halfway through each, and rather impressed with them both. They're written in a very clear, no-nonsense style, with pertinent Zen/Buddhist stories to illustrate the points made. They go into some depth about Buddhist ethics and how they relate to the precepts, both outline the story of Gautama Siddhartha's enlightenment, although the Zen living one then goes on to describe the Zen patriarchs, while the Buddhism one explains about how Buddhism spread, in depth, explaining the commonalities and differences between Mahayana, Theravada, Pure Land, Zen, Son, and so on. Both books are unsurprisingly US-centric, and have a chapter on Buddhism or Zen in the US, but they don't waste too much of the book space on that. Both are very practical-oriented, with exercises to fill out or do by yourself, and they have little "Monkey Mind" sidebars, to provide warnings of common pitfalls.
So, overall, good books. Easy to understand, very interesting, and a bargain at about a tenner each.