A wide variety of concessions range from fast food eateries, restaurants, bars, banks, ATM's, souvenirs, books, language learning software, duty free, and a hotel right inside the terminal!
In general, the larger specialty shops, restaurants, etc. are at the main terminal. You must take a short light rail train towards another hub closer to your A or B gate. There are more shops and facilities at the center of these hubs, but they gradually get less and less frequent as you approach your actual gate. Thus if you are looking for Duty Free goods or specialty souvenir items, banking, etc. look for them before you get close to your gate.