Watch the Blues Techniques 7 online guitar lesson by Brad Carlton from Bluesology 2
It would be pretty hard to imagine playing the blues without bending a string or two. Bending strings emulates a vocalist and communicates the essence of blues phrasing.
This lesson covers correct techniques for bending strings along with a variety of bending options. By improving your "hand setup", you'll gain more security in your bending and your sustain will improve dramatically as well.
You'll also learn some marcato (extreme staccato) exercises, which will improve your intonation.