Watch the 12 Bar Blues Shuffle online guitar lesson by TrueFire from Play Blues Guitar 1: Quick-Start for Beginners
Putting your blues shuffle pattern together in an actual blues progression is the next step. Here you learn the Holy Grail of all blues progressions - the 12-bar blues. Playing this chord progression enough to get it down cold is one of the keys to mastering the blues.
Work through all the changes slowly at first, making sure you are staying in time and not rushing the beat. Practice it slowly until you get it up to speed and then move on to playing it with the band. Now you are making music!