Based on what the reviews say, there are apparently a lot of nice pictures in this book, and it's very well written and easy to read. It goes along with a famous documentary about the Civil War that aired on PBS in the early 90s, but you don't need to have seen that to read the book. I guess if you're really serious about the topic, you might want to check that out too ... Ken Burn's The Civil War. It's around 10 hours long.

The book:

http://www.amazon.com/Civil-War-bestselling-War--based-celebrated/dp/0679755438/ref=sr_1_4?s=books&ie=UTF8&qid=1283088852&sr=1-4

I don't know if it counts as starting from zero though ... to be honest, I kind of doubt if you'll be able to find an American book that's not for children that doesn't assume at least some prior knowledge of the topic. It gets covered kind of heavily in schools, as you can imagine ... I dunno, you might have more luck with a German or an English book? That's all I got. Hope its helpful.