Any Military Truck Drivers?????

I have a very close friend who is in the army reserves, and is a military truck driver. I’m not in the military, so I know very little about the things that are done, let alone what he has to do, besides the obvious…drive trucks!!! He’s not much of a socializer over the phone and I’m pretty sure it’s because he likes to talk about military stuff since thats what’s going on in his life. What I would like to know is this:
*Info about the army reserves program
*The basics (and some detailed stuff) about the career of a military truck drivers.
*What would be their job to do if they were deployed to another country.
And P.S. please don’t direct me to talk to an army recruiter because I’m just interested to know if someone out there has experience in the field without taking that step. Thanks!