We moved over the summer when Katie was 16 months old -- we were moving quite a distance and were between houses for a few weeks and living with relatives, so things were just crazy. I hope you have a smoother move! Anyway, we did talk to her quite a bit about it -- not sure how much she understood, but we did attempt to explain it all to her. When we left our old house, we didn't touch her room until the night before we moved -- we packed it all up super quick so she was only in disarray one night in our old house. When our movers got to our new house, I made sure I sorted through all the stuff and grabbed hers right away -- I actually was able to put her down for her nap in her new room as we got everything set up so quickly. If it's just a local move, ask the movers to put his stuff on the truck last so it's the first stuff to come off (or if you're moving yourself, you can do that too) -- we had our stuff in storage for a few weeks so it was all out of order when we got it. Mark the boxes with his stuff in it very clearly so you can find them quickly.
Just keep everything as consistent as possible - if he has a lovey, special CD he listens to, wind down book, white noise etc make sure you have it. Check the environment of his new room for big differences - we found that her new room was much, much darker than her old one and she kept waking up screaming until we realized and put a night light in her room. That helped a whole lot. I think you also have to expect some difficulty with settling in -- I had to spend a little more time with her at bedtime when we first moved -- just try to stay consistent and realize it's a big change for him so he may need extra cuddles. I think within a week or two, all was back to normal though, when you have such a good foundation I think it's really easy to go back to that.
Good luck!
