I am a newbie too but from searching this forums It has been my impression that any form of cherry tomatoes should do good in az. Other than that people had good success with Roma and the pink belgian tomato along with kellogs breakfast.
People recommend staying away from early girl because the fruit tends to be really small

Cherry tomatoes have by far done the best for me. The larger tomatoes do okay, but I'm horrible at watering them so I usually have a bunch of cracked fruit. My Early Girls last year produced some pretty good size fruit that tasted good, but I had some cracking issues.

This year it's Big Beef and cherry varieties for me. If I had the room I'd pick up a Stupice plant from Lowes. This was on my short list to try, but I never got the seed. If my Yellow Pear seedling croaks then I may pick one up.

There are quite a few tomatoes that do well here, the most important thing to maybe remember is.. days to harvest.. shorter harvest days obviously means, you will end up with more tomatoes when is all said and done. But sometimes you just cant beat a brandywine or beefsteak type tomato. Be prepared to wait 80+ days (sometimes in the 70ish range) to pick those beasts. Siberian and san francisco fog are good seeds to start, they are more cold tolerant then alot of varieties, which means you can get em in the ground earlier, they also mature early.

Olives, sweet 100's or million's, Lrg Red cherries, all do well, and would be up to you.

You'll find what works best for you by trial and error :)
There is a nursery in the "arcadia area"(not sure im allowed to put a name down) that usually has a great selection of varieties ;)

tips from my experience in growing tomatoes...

-inconsistant waterings can lead to cracks on fruit. So don't forget to check moisture, evenly moist at all times, but not sopping wet like a sponge full of water. Remember there is no schedule to water, you water when the plants need it. Weather, humidity, and soil structure will determine a "schedule" for you.
-calcium, do not worry about it, our soil has it, if you are unsure, get a soil test to determine if needed.
-To establish more of a root structure, and you have plants already started, try stripping the leaves almost half way up, including side shoots at leaf stem base, and planting it up to where the leaves you didn't strip are. Tomatoes develop very adventurous roots from the stem.
-Once the tomatoes get some height to them, i like to strip some of the older leaves at the bottom of the plant to allow air circulation through the plant, and prevent stangnant air and fungi build up.
-If growing indeterminate tomatoes (grow and produce fruit until killed by frost) a tomato cage usually wont cut it, think bigger, and know that it will want to grow like a vine.
-If growing a determinate variety (grow to a certain height, bloom, fruit, ripen all at once, and then usually dies, or will notice decreased vigor in plant usually) You will notice they tend to be more upright and bushy, usually max would be 4' or smaller depending on variety, and you wouldn't need a cage necessarily.
-Tomatoes are hungry plants,so feed regularly, and not when you happen to remember to fertilize them.
-High alkalinity in the soil and water CAN create an environment in the soil where a plant can't uptake certain nutrients, so try to keep the pH reasonable by adding compost, and organic type fertilizers.
-Rotate your tomato beds every year, a build-up of harmful organisms can be bad for next years crop of tomatoes. (wont get scientific, google can help ya with that.)

Matt's Wild Cherry ... goes beserk

Roma ... does well, as do other paste types like Amish POaste

Early Girl - fruit size varies wildly

I always plant Celebrity ,Ace and Heatwave,I really don't like Early Girls, they grow fine but are too acidic for my liking.Most Romas do fine as do cherry tomatoes.

Thanks to all that responded. I went to the TomatoFest at Maya's Farm at South Mountain and bought some Black Krim, Paul Robeson, and a Pink Brandywine heirloom. I plan to add some cherry tomatoes.

I am using bone meal just below the transplanted seedlings, per the growers at the TomatoFest.

I grow mine in hydroponics outside, I find that Stupice is a great middle sized tomato that will give you lots of fruit. San Marzano is a roma type that does very well with lots of fruit. Black Krim is one of the best tasting ones, you will enjoy that!