I feel kind of bad about neglecting this thread.
I'm looking at some of the Youtube videos -- those jam tracks don't look too bad, but I honestly don't know that I'd bother to pay for them. YMMV, I guess. I'm just as happy to put on some tunes and jam along to what I'm hearing. Sussing out key signatures isn't too difficult, and you can look up tab to help.
Some examples:
Hootie and the Blowfish - Let Her Cry (GMaj, I - V - IV progression, quite simple)
Cream - Crossroads Blues (12 bar blues in A, a bit quick for beginners maybe)
The Tragically Hip - New Orleans is Sinking (E minor, lots of good spaces to riff over, chord progression's a bit more involved -- follow it
here)
Bands like AC/DC or Aerosmith are good to explore different styles and such, because they have nice big open spaces for guitar. Anything guitar heavy is nice to jam to. Santana, Black Sabbath, Pink Floyd, etc. John Mayer, even. Look for the spaces, fill in the blanks. Start by trying to imitate what you hear, and then branch out into your own sounds. Pay attention to the different licks you hear through various permutations.
I was going to make a list, but found that a lot of my music naturally reflects my interests and doesn't provide the variety that I feel is worth providing in this thread. So I want to turn it around: if you have a song you'd like to jam to and need to know the salient details (key, tempo etc) throw it down in here. I'll have a look/listen and provide the information.