Step 1: Look at a real Fig Rig
Step 2: PVC
Good luck! If you have any questions, I'd be happy to answer them.
Step 3: Extended steps
buy a 10' length of pvc and cut it later, cut all pieces before any glueing (the glue dries fast) and lay out pieces. to cut pvc, use a pvc cutter (pump handle tool).
check out our video podcast on filmmaking over at Take Zer0: Free Online Film School