1) Everything he needs for basic will be furnished. If he takes additional items, he will be lucky if the Army stores them for him.
2) Study very hard in college and get good grades. If you make 2 semesters of academic probation, you receive orders for the nearest Replacement Depot. I made 1 semester of academic probation and received a nice speech that included visual aids. One was an order to the university paying my tuition for the next semester and the other was a set of orders to report the 20th Replacement Depot, Bien Wah Viet Nam. I had a 3.7 GPA the next semester. Just a word to the wise.
3) Your GPA and your course of study affect your commissioning. Good grades in a good major means a Regular Army Commission most likely in the branch of your choice.
4) If he has a scholarship, he will have to take the Graduate Records Exam at graduation. If he does very well on this exam, the Army can offer him an additional scholarship for graduate school. While he is in graduate school he will draw his full pay and allowances as an officer. One trick with this is to go on active duty for 2 years and then go to grad school. Depending on the current time in grade for promotions, you will attend grad school as a 1LT or CPT.
4) If he has the option to attend any military schooling during the summer months, TAKE IT! Some of the past offerings have been Airborne School, Air Assault School, and in lieu of ROTC Advanced Camp; Ranger School. All of these are very good options. The NG may also have additional options for schooling depending on his MOS. Pathfinder was one my son tried for. He actually got slotted for the school, but his unit deployed to Iraq before he got the school. My son chose to deploy with his NG unit, but usually the ROTC cadets are non-deployable.
5) Even if he chooses to not make the Army a career, the leadership training he receives in ROTC and the Army will help him throughout life.
PS Just noticed a later post about MI. This is a difficult branch to get and it limits the schools you may attend. Try to take the Airborne/Ranger in-lieu of ROTC Advanced Camp option. Wings and a Tab are respected by all, even on a non-combat arms type (you get just a little bit of slack when you join a new unit and need to prove yourself to all).