Recently asked by a friend how to find the best target area for investment.  Here's my response:

My rule #1 is school district. Best district = highest, most stable values, longest lasting tenants. 

On a more local neighborhood basis, ask the locals which are the best elementary schools. Normally this holds true around the entire country, except very rural areas.

Then drive and walk those neighborhoods of interest. Ask yourself if you'd let your kids walk there by themselves. You get my drift?  Talk to the folks out gardening or cleaning up around their property. Speak with the mail carrier, the UPS driver, the local hardware store owner, local real estate brokers, etc. 

Make sure to stop in the local coffee shop and hang out a while.  Ask questions and listen to the answers.

Check out the local listings, as well as the local recently sold properties. You'll gain a real feel for the neighborhood, and can make plans accordingly.

It's worked for me since 1980 and still holds true--if we're willing to put in the time and effort. It's the other half of staring at the screen looking at what the Zillows of the internet are showing.

Although I've worked with dozens of out-of-state and out-of-country investors who have bought from me sight-unseen, to me that only works if you know and really trust the person you're working with.  I haven't bought any property I haven't personally seen.  I know, I'm old-school.  But it's worked very well for me, hope it helps you, too.