I'd like to know more about this topic as people often discuss it with me. What is a good book for me to read to gain a better understanding of Tibetan history?
Using my elite Amazon search skills, I discovered Tibet: A History by Sam van Schaik, which looks like what you want.
Personally, I'm a fan of reading literature and/or biographies, as I find concrete stories give me a better handle on the more abstract cultural or political issues covered in a regular history. Sardathrion's books look interesting, as does Tibetan Diary by Geoff Childs.