I'm (still) going to write a blog post about this soon.

Again, the BiggerPockets store has some books for this or you can learn by watching podcasts, reading blogs, and interacting on the forum.

Below is from a BP blog I wrote about this. 

YES, we may be a little biased, but check out our blog here on BP comparing Detroit to other cities and Deep Dives on Metro Detroit cities & neighborhoods: https://www.biggerpockets.com/...Your biggest question shouldn't be WHERE to invest, but HOW you will invest!

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

In the meantime, if you're in need of a quick inspiration read, feel free to check out my blog post here:http://www.biggerpockets.com/blogs/6240/blog_posts/42502-the-four-qualities-you-must-possess-for-successLooking forward to connecting with you and seeing you around the forum.Very respectfully,

This particular topic has been unpacked on the forums, blogs and podcasts in great detail.  

http://www.biggerpockets.com/blogs/3225/blog_posts/26426-mentor

I start this blog off this way because now I have a friend who wants to join me and its a really good feeling.

However, keeping your homes is a different story and I wrote a blog on here about keeping your homes.