ASLU (Life Print)

ASLU is an online American Sign Language curriculum resource center.  ASLU provides many free self-study materials, lessons, and information as well as formal tuition-based courses.
 
ASLU has been offering online sign language instruction since 1997.  The program began as an effort to support parents of Deaf children living in rural or "outlying" areas without access to sign language classes. 

You are welcome to self-study from the various publicly available Lifeprint.com lessons for free.