So far, I've read mainly three or four Lebanese history books. They were however all in French... The one I'm reading now is "La déchirure libanaise" by Nadine Picaudou. I also read "Histoire du Liban contemporain" by Georges Corm. Dunno if there's a translated version for any of the two books...
I am sure, however, that there are many history books out there that are quite good. As long as they seem neutral and are written by historians, and not politicians or ex-militiamen, they should be good enough...
Good luck!