You posted in the wrong category. Lots of people do. I found your Q by searching for "Ancestors".
======================================================
This is a long, general answer about beginning genealogy, with some links. Genealogy is a fascinating hobby, but it usually takes more time than most young people are willing to spend.
Genealogy is the most popular hobby on the Internet for people over 40. As an example, Cyndi's List (cyndislist.com) is a web site with nothing but links to other genealogy sites. She has over 250,000 links.
The next two links are to the two largest free data bases on the Internet. Family Search (familysearch.com) is run by the LDS Church - the Mormons. RootsWeb World Connect (worldconnect.genealogy) is a collection of genealogical data that other genealogists have uploaded.
Try your two surnames in each data base - your father's surname and your mother's maiden surname. That will give you a feel for how much research has been done on those two surnames. Even better, if you can, call your grandparents and ask what THEIR grandparent's names were - maiden name for the ladies. Their birth day and birth state will help too. Those 16 people are your great-great grandparents.
Most Yahoo! users are 20, give or take 10 years. Most people have children between the ages of 20 and 40, which averages to 30 years per generation. So, if you were born 20 years ago, your mother and father were born 50 years ago, your four grandparents were born 80 years ago, your eight great-grandparents were born 110 years ago and your sixteen great-great grandparents were born 140 years ago. (Those are averages; your results will vary. If you can get the names of all 16 of your great-great grandparents, you should be able to find at least one or two by name in one of the data bases.
The fourth link (superpages) is a web-based phone book. It will tell you how many people with your surname have listed phone numbers in the US.
The last link (begingen.html) is a page on my web site with some hints for beginners.