Watch the Down and Out online guitar lesson by Jeff McErlain from Essentials: Chord Tone Soloing
Since this song has been around since the 20's, I believe there are many fantastic versions to listen to, some more jazzy than bluesy. Check out Bessie Smith, Scrapper Blackwell, Nina Simone, Sam Cooke, and BB King to name a few. Everyone has their own approach, with lots of great stuff to learn from each of them. When watching and learning my solo, take your time and make sure you see each of the chords inside the solo as you go through it. One of the themes of this course, as you'll know, is to envision the chord shapes in the position you are soloing in. This is the way most guitar players I know think when they're soloing. We're not thinking scales, for the most part I'm thinking about the note in each chord in which notes I can play around them. This is transformed my guitar playing and overall musical ability. I'm not sure when scales became the be-all and end-all of improvisation, to me it's all about chord tones.