The "greater" Phoenix area is BIG! What city are you moving to? Phoenix proper or a suburb?

If I were you, I'd seek out a bike co-op. There is one in Phoenix called The Rusty Spoke and one in Tempe called Bike Saviours. These are "bring your bike in and the tools & assistance from a mechanic are free and the parts are cheap" places (non profits). If you need new higher end parts you can buy them from any local shop really (whichever one has the best prices) and then bring it to a co-op and learn how to actually maintain and fix your bike so you're not dependent on a shop to do the job.

When I do visit a local bike shop, I go to Landis Cyclery. Tempe Bike is good (the east one, where a mechanic named Marcus works). The thing about bike mechanic'ery in Phoenix is that of the mechanics I know from local rides, it's a bit incestuous in that again, those I know personally, have worked at several different shops.

We also have several Performance Bike stores here, a national chain, which leads some to complain that they're not a true LBS and take business away from local shops. I buy all my tubes at Performance as they're much cheaper and they're often on sale. All tubes come from asia and unless bike shops are buying really low quantity and paying higher prices, there's no reason for them to mark them up as much as they do.

It will really come down to what's the best bike shop that's a reasonable distance to where you live/work/ride.

If you're anywhere near Tempe check out our website http://www.biketempe.org, we're a local non profit bicycle advocacy and social rides organization.

-Tom