Contact American Barefoot Club.
I built my first ski jump ramp with plans purchased from AWSA. Barefoot ramp is smaller, less complicated, and much less expensive. Shouldn't be a difficult project.
You can get some idea here in the appendix section of their rulebook online:
http://barefoot.org/abcfiles/ruleboo...09Rulebook.pdf
Jump ramp/course info starts on p. 101.