Slow Six,
I can't be too much help to you even though I live in Phoenix. I don't have a need to camp here. However, the entire Phoenix valley is loaded with RV Parks. The greatest number of them is in the south east valley, namely Apache junction/Mesa. There are a lot of RV related businesses in that area, also. You will find more likeminded people in that area.
The Phoenix valley is a large area with around 3. 5 million people. If you would prefer a smaller, more rural area for your stay in AZ. , you might consider Casa Grande, AZ. which is located on I-10 about half way between Phoenix & Tucson. It's about an hours drive to either city from Casa Grande. Lots of RV Parks there, also.
Thank you for choosing Arizona as your destination. Glad to have you here. There's enough sunshine & warmth here for all of us.
If you are interested in diesel related activities, there is going to be a big diesel drag race on the west side of the valley on Saturday, 3/10/12. It's a fun event that draws racers from all over the country, including Canada. This will be a national event.
Joe F.