Searching for your ancestors and your history is a popular hobby. Signing up for Ancestry.com can be too expensive for some families on a strict budget. There are of course free ways to start researching your family tree. Here are a few free options!

Here is a great quick free site that lets you fill in your Family Tree (3 generations). You cannot save it but you can print it! This is a great place for kids to start. Instant, free , visual and printable.
PBS Kids - Way Back, Family Ties. You can download the program and save it so you can come back anytime or you can just fill it in online (print but not save).
Family Searchoffers some free census records and other places to get started with your research.
Family Echo is a free web program that lets you enter extensive information and create a visual family history. You can save your work, share your progress, print, add birth and death dates, biographical notes, occupations, photos and more. I was really surprised at how good the program was for FREE. True, Family Tree Maker may offer more complete options, but this is a really great place to start when you are on a budget!
