Best places to buy for rentals would homes in areas that have the easiest commutes to Phoenix/Sky Harbor Airport area, or north Scottsdale. The Valley's largest employers are located in these areas.
We still have a great amount of homes selling each month, and a strong number of families that need rental housing. The Phoenix metro area has a high population growth rate. Lease-purchases are becoming more attractive here as well; because those families that were put out of their homes from their adjustable ARMs need a new place to live, yet don't want to 'just rent'.
I have had several California investors in the last couple of years. There is many good places to find property that would be good rental homes/condos/duplexes/ etc. What are your investment criteria? Are you looking for anything in particular? Will you be managing the rental property yourself? How much are you looking to spend? What are your goals for the property?
There are so many deals that are coming available now. Short sales, lender owned properties, etc. Just think about what your goals are, your criteria and then start from there. Good luck
Good investing and welcome to our Beautiful City and State