My previous Jazz Masterclass went a bit wrong because some people used it to start a flame war and turned it into shit.
Still, that's not the end of it. I'm making a similar thing on my blog where people can't make flame wars and I can moderate comments if needed.

So, few words to cover some theoretical stuff:
I strongly recommend to take a look over musictheory.net and 8notes.com/theory.
For more specific jazz theory there are some useful links also, tamingthesaxophone.com/jazz-theory and jazz-styles.com (website in French, but Google translator can fix the problem).

And now the lessons + backing tracks:
1 - Blues Tutorial - jazz theory, 3 free backing tracks, 2 famous jazz standards and a rock/ shuffle blues, music sheet.
2 - Cantaloupe Island Jazz Tutorial - backing track, info about song, music sheet.
3 - Blue Bossa Jazz Tutorial & Free Backing Track
4 - Footprints Jazz Tutorial & Free Backing Track
5 - II-V-I Exercises for Trumpet (Bb)
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Other Resources:
Guitar Little Chord Helper - something to print and write down your chords.
Jazz Brass Loops Pack in C 120 bpm - All parts in this pack are in C, mostly Blues scale and all are in stereo acidized .wav format, 16 bit, 44.1 khz sample rate, 120 bpm.
Jazz Trumpet Loops Pack in F 90 bpm - All parts in this pack are in F, mostly Blues and Dorian scale and all are in stereo acidized .wav format, 16 bit, 44.1 khz sample rate, 90 bpm.
Muted Trumpet Solo Loops in C 100 bpm - All parts in this pack are in C, mostly Blues and Dorian scale and all are in stereo acidized wav format, 24 bit, 44.1 khz samplerate, 100 bpm.

To be updated every now and then.