Hear My Train A Comin' is pretty amazing.
Study his licks. It's in the key of E (if you leave your guitar in standard tuning to play. You don't have to tune down all that way unless you want it to sound exactly the same as him). Maybe learn the intro as a launching point for the licks.

Other than looking at individual songs, just play around with 12 bar blues with a basic shuffle. There are plenty of lessons on this site to teach you how if you don't know already. Check the video lesson section too for 12 bar blues lessons.
any robert johnson tune, be prepared to be mind****ed for a couple weeks
"When you got a good friend" and "Sweet home chicago" are some easier robert johnson songs, minus the licks while he simotaniously plays a shuffle :O

Rollin Stone by Muddy Waters is good as well.
Any Robert Johnson song aint exactly easy, unless you simplify em a lot..

Still, learn the standard blues shuffle in all keys and go nuts with googling blues standard lyrics