I am planning to visit MWU, AZ later this month to find apartment around the campus.
Once I arrive at the airport, would I be able to find car rental service?
Do I just go to info desk of the airport so that they can direct me to the rental service?
And if anyone knows about either studio or 1 bed room apartment that is less than 10 min drive away from MWU, please let me know.
It's really easy to rent a car in Phoenix. I would recommend looking at various websites online (Budget, Avis, National... along with the discount sites like Orbitz, Expedia, travelocity, etc). You may be able to find a deal with airfare/car rental. When I rented a car in Phoenix in October, it was abut $130 total (taxes, insurance, etc) for a one day rental.
When you get to the airport, you have to take a shuttle to the car rental center, which is a couple miles away (the shuttle's free). It's HUGE, and has every car rental company you can dream of. Find your rental agency, sign the paperwork, get your car and go.
As far as finding an apartment, I would recommend doing an apartment search in the Glendale area. My wife and I just bought a home there, and that's what we did. We figured out our price range and which homes we wanted to look at while we were there. If you did that, made a list of apartments to view, and make notes as you view them, it will make things easier when decision time comes.
Hope that helps, PM me if you want more info.