He'll most likely have access to email and that is great but make a point of sending him actual letters with photos in them. Even though he can view photos online, he can actually keep a few photos on him anytime he likes. Also get all of his/your friends and relatives to send letters and videos. Its amazing what it will do. Actually holding things from home will really boost his moral.

While I was in the military, my family had old friends I hadn't seen for a while send letters. It really got me though some tough days.

As far as giving him something before he leaves, I suggest a really good camera. Tell him to take photos of everything. Hope this helps!