R.R.
Bed guards or start him out on the mattress on the floor, with a baby gate in the doorway and making sure his room is completely childproofed in any event.
Also consider getting him a Cloud B Night Light that projects constellations on his ceiling, it will give him something to look at as he relaxes and falls asleep:
http://www.amazon.com/s?ie=UTF8&rh=i%3Ababy%2Ck%3Atwi...