The blues is one of my favorite genres on guitar, I teach it to students all the time. Why? Because it's easy and loads of fun. If you're at an intermediate level, you're already at a stage where you can play astonishing blues riffs and solos like BB himself if you know some basic blues guitar techniques.
And you know what, these blues techniques are mostly basic guitar techniques that you are probably familiar with already. If you can already play some of the more complicated songs in the guitar song lessons section of the site, you are at the stage where you might consider getting some blues guitar lessons, since you are already at the level where you could be playing the blues.
But enough rambling, here are the guitar techniques you'll need to master if you want to play blues: