I agree with Fly. IMHO, its essential that each of you have a CC.
1. In emergencies, like driving cross-country and your Mustang (Navy) or truck (USMC) breaks down, you might not have enough in your checking acct at that moment to cover it.
2. When renting a car, not only do the rental companies want one, but you get free additional insurance provided by you credit card company, free.
3. When ordering anything on-line or over the phone, never, never, never use a debit card. If someone gets ahold of your info, your checking account will be emptied within seconds, and you will have no recourse. With a CC, you can call the card company within a certain time and have the charges removed.
The secret to all of this, is to have a good CC, and never use it! If you absolutely must use it, pay it off immediately.
Shop around all you want for the "best" CC, then come back to USAA. They understand the military, and will work with you when you need help. While you're talking to them, ask about opening an IRA.