My boyfriend wants to go to the national guard.. what should i be expecting?

My boyfriend wants to go to the national guard. He told me he would be gone for about four weeks of basic training, and that if he went over seas it would be to help victims of earth quakes and stuff like that. I'm not really that educated about that kind of stuff, so some questions is, is that what kinda of stuff would he be doing? Is there any chance of jim getting hurt? What will his communication limits? He's going through his junior and senior years. Help me please, i'm worried about it.. but i don't wanna seem selfish that i don't want him to go when i know its something he wants to do....