There are many sites you can go to. The one I frequent the most is a genealogy forum. Below are some sites I go to often...
http://genforum.genealogy.com/
http://www.cyndislist.com/
http://www.familysearch.org/eng/default.asp
http://www.familytreesearcher.com/
http://www.rootsweb.ancestry.com/
http://www.cousinconnect.com/
http://freebmd.rootsweb.com/
Then if I'm stumped sometimes I'll type in last name and the town and/or country they were born in and a whole bunch of info can be found.
I hope the above links have helped. I haven't been to this site in awhile so forgot to check back on my original message. I did find out that one of my husbands great, great (don't know how many greats) married Robert the Bruce, and I found that my grandmother's uncle was the mayor of Preston England. I've found a website that has pics of him. Also is interesting to find out what type of people our in our history. One of my husband's great uncles dressed as a woman to leave ireland (don't know why), and one of his great great uncles was an outlaw from the wild wild west days. It's great fun.