Linda, here are some links to free folk-blues stuff from a fellow Marylander (I'm over on the Eastern Shore) that addresses some of the concerns you brought up (hand pain, theory, playing & singing, etc.):


The How and the Tao of Folk Guitar
An open source guitar book.


Folk Guitar
Four half-hour video lessons. Lessons five through eight will be going online sometime in January or February.


The Subway Shuffle
Blues guitar from the Philadelphia subway system.


Another Subway Shuffle workshop - only this time on YouTube.

-Patrick
howandtao.com