Borrow a book about American Sign Language from your local library. These books are heavily illustrated and show the correct hand positions, shapes and movements you need to learn to communicate effectively. Look for books that contains a CD/DVD video so that you can watch how the movements are performed and follow along.
Enroll in a free ASL class at a public library. Many libraries offer free sign language classes on a weekly basis. Contact different public libraries in your area and ask if they offer free ASL classes. If they do, register quickly because these classes are offered on a first come first serve basis and often fill up quickly.
Contact a large hospital or medical center near you such as a children's medical center. Many large hospitals offer free ASL classes. They also have their own libraries, which you may browse and from which you may borrow ASL books. The procedure for registering and borrowing a book from a hospital is similar to your local library.
Learn ASL free by video chatting with people who know ASL in a social networking site such as MySpace or Facebook. Log in to your favorite social networking site, join an ASL group and post a message on the group's wall, asking if anyone is interested in helping you learn ASL via video chat, using your favorite instant messenger. People can communicate with you by typing on the keyboard and show you how to perform the hand signs correctly by using a web cam.