M.L.
Our 14 year old bichon went blind in a new home we just purchased.
Try and keep furniture arrangements somewhat similar during the unpacking process, try and keep your dog kenneled or leashed to a table leg or something so all of the boxes and such won't throw him off. Get one room done quickly so that your dog can become familiar with that layout. Just walk the dog around, show him the corners of the couches and such.
Using the bell on the back door is a good idea too.
Our dog would get stuck behind things, for instance she would walk around furniture and then get stuck behind the wall of it, so make sure that there aren't small crannies behind tvs and such he can get stuck behind.