Rich Holtman, KD9ANU, has prepared an extensive presentation on the WinLink system and how to get it working in your shack.
You can find it here.
San Diego ARES has a set of short video clips on using WinLink.
There is a video of a presentation on how San Diego ARES recruits, trains and uses WinLink here.
LAX ARES has a series of Winlink Training Videos