In addition to the official routes already mentioned, I've had some amazing results in Ancestry.com. I was able to track down my dad's WW2 and Korean War information. This included details from his boot camp, follow-on ("A school, we'd call it) training, and overseas deployments with Marine aviation. About 200 pages of original records. I also found some basic info on my father-in-law's time in a German POW camp, and "Missing in Action" reports on an Army Air Corp relative.
If your friend has an Ancestry subscription....or a guest subscription...or knows someone that has an Ancestry account... they can access a huge data base of military records.
Just recently I went to the local Veterans Service Office trying to find some info about a Navy Unit Commendation for where I was stationed at NavFac Ramey in the late 60's. The VSO said that the first thing I needed to do was fill out a form he had and would fax to some DOD office (or whatever). He said if they respond, it would include my entire military service record - bases, dates, etc., and would be mailed to me and said it was commonly referred to as "page 5" of this form. He said it might take several weeks - you know how the gov-mint works...
So, I'm waiting to see if I get a response, and I'd recommend to you that you first start by contacting your local Veterans Service Office. As far as I know, every state has them, but I couldn't guarantee that, as they are State government employees (not military) whose job it is to assist veterans obtain information.