Out of Pocket Expenses

With the exception of airfare, are there any hidden expenses that parents need to be aware of during the first year at the USAFA?

Your cadet will most likely want a separate monitor for their desk - the laptop screen is small and most cadets get separate monitors for their desk. However, there is a limit as to the size it can be, and I don't remember what that is right now. Our son also purchased a printer. Parents who go to acceptance day often bring the monitor & printer; we just ordered it online and had it shipped to him.
Unless you're local - anticipate mailing care packages to them at least their first semester. USPS flat rate priority mail boxes work well for that -- stuff it full of stuff and it's one price, no matter what it weighs. C4C's can't get packages until Acceptance Day.
Son also bought a blanket (they sleep on top of their made beds, or even on the floor) - I know some bought compact sleeping bags.
Then there is ski/snowboard winter gear - the cadets can go skiing/snowboarding on free weekends.

forgot to add -- TEXTBOOKS!
C4C's can add first semester textbooks to their funny money account (the loan they purchase all their uniforms and such with), but after first semester they are on their own for purchasing their textbooks.
They don't have to use funny money, can buy themselves used from other sources (amazon, half.com, upperclassmen) and can even rent from some places online.

HD Monitor (up to 24"), all-in-one compact printer/copier/scanner and cable, good sleeping bag, ceramic electric space heater, a good pillow, good electric shaver (can have this during Basic). Other stuff is not until after basic. All are good high school graduation gift ideas. He took back computer speakers we gave him for Christmas but he will not be able to use them until after Recognition.

They are allowed to have ski clothes/gear. We took our son's ski clothes up parents weekend so we did not have to ship them, and he did go skiing before Thanksgiving so it was good that we took them early.

I'm pretty sure I spent over $200 this weekend. I don't know the exact number because I'm afraid to check my bank account.

Anything you want to do on the weekend is on your dollar.

Cell Phones

What about cell phones? When can he have that? Our contract might be up soon and I don't want to extend his if he can't use it for a year

They take their cell phone from them when they in-process; the basics get them back for doolie day out and then they are taken away again after DDO is over. After acceptance in August some squadrons let the C4C's have their phones, but it seemed most did not. They started getting them back for weekends in late Aug, and had them for PW. After that our son's squad took them back until their knowledge test scores improved. Just when they thought they'd have them for good, they lost them again in early Nov for a little while for some infraction. He's had it back though since mid Nov.

I think it's important to add that monitor (max size 24", according to CSP), printer, skiing equipment, weekend spending (movies, food), cell phones, etc. is completely optional. You don't have to spend a single penny if you don't want to. It is definitely possible to live without receiving any parents' money, although it's nice. Plus, most of the luxury items mentioned above could be purchased with your pay, and still leave enough money for books after first semester. For 4 dig classes books shouldn't cost more than $600 even buying them all new from the bookstore.

Also, cell phone prevs are completely up to the squadrons. Our squad gave them back after PW for weekend use only, then we got them all week after Prog, if we weren't on ac pro (2.0 GPA or below).