Yup, Red-Eared Slider. The most common turtle you will encounter. These buggers have infested just about every fresh body of water in the US, and probably most of the world. They are bred in vast numbers and sold for the pet trade (which I think should be illegal, but that is another story).

The hardest part of turtle care is filtration. I use an Eheim Pro II external canister filter and it ROCKS. I actually have an extra one. If you are interested in upgrading I will give it to you for a steal.

The next thing to make sure you have after clean water is a basking spot with a UV lamp. PetCo carries a lot of good reptile stuff, but their prices are TWICE that of most good online shops. I buy all my stuff from these two places:

The Bean Farm
This place sells the good UV spectrum bulbs at nearly HALF the price as PetCo.

For filters and quality service, go to:
Drs Foster & Smith

With turtles, the more space you give them, the better (happier) they will be. For substrate you can use thoroughly cleaned PlaySand or aquarium gravel. Driftwood makes for good basking areas.

Keep the tank area in a warmer part of the house (should be easy in AZ) and away from cold drafts. Water should be kept around 76 degrees for this species, a little warmer or cooler will be fine too. These guys are super hearty.

As for food, I always offer a variety. For Trachemys scripta elegans (your little guy) offer Reptomin regularly and any other over the counter aquatic turtle food. The Reptomin that comes with freeze dried shrimp will be gobbled up with joy. I also feed earthworms and the occasional minnow or goldfish (gives them something to chase and keeps them busy). I would also chuck in some Romain lettuce now and then, as these turtles will sometimes enjoy real green stuff. Just don't overfeed, otherwise you will end up with rotting food in the tank and the water will fowl quickly.

I think live plants are great. I just think that it will be hard to keep any live plants with a Red Ear because they will eat them and tear them up.

Good luck,

Bart