How can I learn how to read the market?

[Account Closed]

I am in the process of saving my down payment + cushion funds for my first investment property. While I work on that for another year or two, I am focusing on learning how to get started looking for, choosing, purchasing and renting out investment properties. 

 My biggest question is, how am I supposed to know what state, county, city, etc., is the best place to purchase and rent? I am living in California and I am not at all opposed to taking my business out of state, however I believe it will be easier to stay "local" for my first experience. I plan to purchase a duplex for residential purposes for the first year while renting out the second unit, and then begin t rent out both the units as my residential prerequisites are fulfilled. I am open to suggestions and fluctuation in that plan, however. Any advice?