What is the best guide book for Syria?

I will be visiting for a day or two while on vacation in Beirut this August. I plan to stay in the Damascus region, if I do stay overnight, and my primary interests are history and modern culture. Aside from the best guide book, any other tips (including where to stay, and how to get through the border the fastest - I will have a Visa in advance ((I am an American, traveling with a Lebanese via car)), is much appreciated!). I used the Lonely Planet Guide to Lebanon on my last trip over there, and it was phenomenal, but the San Francisco guide kinda sucked, meaning I'm not 100% sold on Lonely Planet for every location. Thanks all!