Musistic is a platform agnostic collaboration platform and they have started Musisitc University, a site with tutorials and articles on a range of different DAWs.
For Pro Tools here are a sample of what they are offering right now...
- Musistic University: Widen Effect Using Pitch II
- Musistic University: Pro Tools Track Types
- Musistic University: Adding sub-kick to your mix
They also have a section on how to Send & Receive Audio in Any DAW with Musistic covering Ableton Live, Logic Pro X, Pro Tools, Studio One, Bitwig Studio, Mulab, Reaper, and Traction.