The II V I ( 2,5,1) progression is commonly used in jazz music and resolves nicely to the tonic chord. In the Key of (A) The II V I progression would be Bm | E7 | A7.
Below is the basic 12 Bar Blues in the Key of "A"
A7 | D7 | A7 | A7 | D7 | D7 A7 | A7 | E7 | D7 | A7 | E7.
If we add a II,V,I progression to the basic 3 chord blues progression we would end up with
A7 | D7 | A7 | (E-7 A7) | D7 | (B-7 E7) | A7 | (F#-7 B7) | E7 | D7 | A7 | (B-7 E7).
Try this out at your next blues outing and watch your band mates turn their heads.