I don't have any pictures handy. It would probably be wise for you to download a copy of the Hobie 20 assembly manual from this site.
For rigging the the mast rotation limiter, the stock method is set up so that you can adjust the rotation from either side of the boat. Tie a stopper knot in one end of the line. Pass the line through the grommet on the outside edge of the tramp (next to the cam cleat mounted on the tramp rail) under the tramp and up through the big grommet in the middle of the tramp, through the shackle on the rotation arm, back down through the center grommet, then back up through on the opposite side. The cleats on the tramp frame allow you to set the line position. The shackle on the rotation arm allows you to disconnect the rotation line without unthreading it.
Notice, the stock rotation limiter is not rigged off of the boom. If yours is rigged from the boom, then it's not set up as stock. There was also a stock positive rotation inducer that was rigged off the boom. But nearly everyone eventually went away from it because there are better methods that run automatically and won't break your mast.
The free end of the mainsheet line is used for the traveler line. Pass the line through the cleat and fairlead mounted on the traveler car. Tie off on the pad-eye riveted in the center of the rear crossbar using a stopper knot. Pull the line in to center the traveler, ease it to let the traveler out.
Easing the traveler is done when sailing downwind or when you're overpowered. It allows you to open up the angle of the sail while still sheeting hard to flatten the sail and control twist.