generally 12 bar blues in A goes like this:
D)-2-2-4-4-2-2-4-4-5-5-4-2-
A)-0-0-0-0-0-0-0-0-0-0-0-0-
and repeat.
mess around with it a bit it gives a you a good feel for a solid blues rhythm. its also good bc you can play with a much more experienced player and he can easily solo over this...