This site is done by the same people who do the Guitar Techniques magazine (probably the best guitar mag out there).
They have original backing tracks that are professionally recorded and come on a cd. Excellent quality tracks!!! They also have the "Original" and "Jam with" series. These come with note for note transcriptions as well as accurate backing tracks (minus the guitars) of the original songs from bands like Metallica, Van Halen, Bon jovi, Satriani, Pink Floyd, etc., etc., etc.
Definitely worth checking out! They are a bit pricy though! I suggest checking out Music Dispatch
and buying any of the Total Accuracy series you can get from them. They are sold for retail price on the Jamtrax site and only about half the cost at MD!
Unfortunately, not all the titles are available through MD (or any other bookstore that I could find).
You can also buy individual backing tracks to songs online in mp3 form, BUT it is extremely pricy!
$7.00 for one track if you go the individual track route!!! Kind of sucks because I just want the backing tracks, I don't need the transcriptions!
Be sure to check out there sample tracks, as well... cool stuff!
William - GuitarShred.com