I'd also join the local investor facebook groups because they are often posted there as well.

I’m in the process of advertising and listed in a local Facebook buy sell and trade.

You can also check their reviews online at Google, Facebook, or Yelp.

My wife and I find alot of our contractors by asking for referrals on facebook.

My daughter simply posts the vacancies on facebook & they are filled immediately.

They're on Facebook groups (check out "LDNonFIRE"). 

If you can't find any in your area check Facebook and Meetup.com.

Very polite, proactive in the application process, had good references from previous landlord, has good/stable employment, and when I looked them up on Facebook their information matched everything on their application.Unfortunately, they are not able to complete the screening due to a complete lack of credit history (young applicant with no credit cards or, evidently, student loans).

Check em out facebook.  

I connected with a Real Estate attorney, had him write me up a contract, posted on facebook & craigslist and the phone would not stop ringing.