Genealogy websites make ancestry information accessible in a way in which it wasn't before, and there are literally hundreds of options to choose from. The larger websites contain the most comprehensive information, but a lot of detail is hidden behind a paywall and you'll have to choose a monthly subscription or pay-per-view option to access all the records. If you're prepared to put in the legwork, however, you can find most of what you're looking for completely free of charge.
Completely Free Online Resources
First, there are lots of excellent free genealogy websites that are a good jumping off point for your family research. These include the websites Familysearch.org, a nonprofit family history organization run by the Church of Jesus Christ of Latter-day Saints, and Rootsweb.com, a collection of user-generated databases and message boards that people use for genealogy chat and to share research. Try Googling "free website to find ancestors" as new resources pop up all the time. None of these sites is guaranteed to hold all the records that you need, however.
When you have done your basic research, it is time to investigate official records, for example, those containing military records, census records, immigration records and the Indian Rolls. The National Archives is the central repository for all of these databases. Most are now digitized and anyone can search for free online – the website has some useful guidance and search tips. Be sure to know your ancestor's full name, date of birth and location before searching these records. Without this kind of background information, you will have trouble identifying the correct person among thousands of possible matches.
Free Trials Are Your New Best Friend
The bottom line of genealogy research is that you are going to have to pay if you want to access all the good stuff in a single location. Paid sites hold all types of birth, marriage, divorce and death records, military and prison records, newspaper archives, census returns and more that would otherwise take weeks or months to track down individually. Luckily, most sites, including Ancestry.com, offer a two-week free trial period so you can learn about your ancestors for free. It's a good idea to print the results of searches you do during this period as they will be lost when the trial comes to an end if you do not take out a subscription.
If, like millions of immigrants, your ancestors passed through Ellis Island or its predecessor Castle Garden, you may get some quality information from their online databases. You'll probably need an estimated date of arrival to parse the records. The Library of Congress contains images and transcripts of thousands of historic newspapers from 1789 to 1943. You can search by name to find out if a specific ancestor did anything newsworthy. If you're looking for a tombstone, Find a Grave is a free website where you can search millions of burial records from around the world.