I don't envy you your task. I have been trying for some time to trace my ancestors but have had little success.
You will see my entry on this site from 21/1. My ancestors come from a village called Kfarsghab in the north of lebanon.
There is a site called www.leb.org, which is a lebanese white pages with over 48000 members. If you know your village you could search the site. You can also leave a message similar to this site. You can also search by your family name and go from there. Many people have had success on this site finding family etc. Anyway, its a good place to start.
Hope this helps.If you find any other good source please let me know. I live in Sydney Australia.