Choosing an out-of-state location

[Coleman Cox]

Hi All - I've recently been bitten by the real estate bug; I've just finished Brandon Turner's Book on Rental Property Investing and am all-in on BiggerPockets. I'm still in the information gathering stage at this point but want to start analyzing realistic deals.

I live in the Bay Area of California which is outside of my budget, so will likely be taking on some form of David Greene's long distance property investing. I'm having trouble focusing on a handful of key metrics that will help me narrow down my analysis to a few broader markets (city / state). I'm thinking historical property appreciation, price-to-rent ratio, and maybe vacancy rates are a good place to start. Does anybody have any other ideas and/or sources of information for the metrics? Or does anyone have a method for choosing markets to enter when going the long distance route? Thanks!