Please check out my "Bone Head Blues" lesson #'s 8030 and 8032 for more beginner blues phrasing ideas.
This info was originally posted by me in a FretBuzz forum, but I think it also makes a good beginning lesson.
AARRGGGHHH!!! Stop thinking "scale", and start thinking melody and harmony sounds with the chord being played.
Sorry, had to get that out of my system.
Blues should be your guitar singing a melody along with your soul. Learn to sing/hum what you want to play, then find the notes and work on getting your fingers to do what they need to create that sound.
The nice thing about blues is all of the notes you need are close to the fingerings of the chord, usually a dom7 (E7,A7,B7 etc) chord. You have all the notes to choose from, except maybe the maj7, and even that rule can be broken depending on context/phrasing.
Take an A7 chord for example. Every note except the G# can be readily used for bluesy phrasing.
Yikes!! I thought this was a beginning lesson? What's with all those notes?. Well, you could break out the metronome, and learn to burn this "scale" up and down as fast as possible, but that wouldn't sound very bluesy or musical, would it? Go onto page to and find out how to take a small chunk of it and use it for some simple bluesy phrasing?