The easiest book that I found to understand was a little book put out by Chick Publications.
It was brown and it had scales on the front. I think it was called "Let's Weight the Evidence".
YEP - that's the one
http://www.chick.com/catalog/books/0184.asp
It's not a "scholarly" book, but it will answer the questions of one that is seeking the truth. It also is outdated, so it doesn't have the NKJV or ESV in it.