I agree with the one room at a time. As was already suggested, watch carefully, and see what he's interested in.
I just let Lexi into the living room two days after Christmas. I couldn't believe that she didn't go after the ornaments on the tree!
When she is exploring new areas, I keep her harness and an old leash on her. (Old, so the beautiful leash from chattiesmom doesn't drag around on the floor and get all dirty!) That way, if she gets into something she shouldn't, or tries to get away, it's easier to catch her by grabbing or stepping on the leash. In my room, she loves to go under the bed. Without the leash, I might have a heck of a time getting her out.
She will usually come out when I tell her to, but if she's not in the mood...I still have the leash!
Good luck! I bet it will go better than you think.
