Videos showing and explaining in details the features of GpsarPro are just available here :

Chapters are as follows :

[1] GPS track data loading
[2] Import data from GT-11 or GT-31
[3] Filter and adjust a track
[4] Using speed-graph
[5] View 2D settings
[6] Managing several view windows
[7] Main Tool buttons
[8] Speed performances & send to server
[9] Calibrating a map
[10] Map auto creation/calibration from internet
[11] Define and Observe a Regatta

Chapter [8] is dedicated to GPS-SpeedSurfing users, with the whole procedure to compute results, send them to GPS-SS, and then edit and validate them once on GPS-SS.

Chapters come both in English (sorry for my limited english skills) and French voice versions.

If you think some more chapters are still missing, please tell me, I'll make them.