B.B.
I agree with keeping it simple. My husband is in the U.S. Army and just returned home a few months ago from a 15 month deployment. We have 2 children. Our youngest had just turned 4 when he left and we tried to keep it as simple as possible. We talked to her and told her that Daddy had to leave to work and would be gone for a while. Also, we did not have this luxury but a lot of times the guys can get internet in their rooms. My husband was on a Special Forces unit so they were not allowed to have internet in their rooms, but alot of others do get it for a fee. If that is the case with your brother, then buy him or send him a webcam so your son can see him on webcam. Keep pictures of you brother around for you son to see and if you brother can call him occasinally that will help to. If you have any more questions, feel free to send me a private email and good luck!
B.