Where can I find the AZ county building codes?
It looks like they are using the 2012 Edition of the International Residential Code (IRC), See here:

https://www.maricopa.gov/2262/Construction-Codes

However, for your application, You want to check the ZONING ORDINANCES rather than the BUILDING CODE. Your county Planning Department can check to see if the area you want to build in is zoned for containers. If they are, they can tell you setbacks, maximum lot coverage, etc. 

Also, I’d check the CC&amp;R’s (covenants, conditions and restrictions) for the area you live in. Some CC&amp;R’s don’t even allow dish TV’s exposed to the street. Be careful on what is allowed...