I have been managing a relative's property from a good distance using a virtual phone number and a gmail address which is the property address @gmail.com. I set up a property website through Wix, then posted on CL, Postlets, (which sends out to Zillow, Trulia, and Hot Pads) and Zumper. All posts pointed to the website for more detailed information.
I was very open and upfront about rental qualifications, including no prior evictions, credit score of 600+ and verifiable income needed to be 3 times monthly rent.
ALL contact was done by email (I am going to update the post I did on this a month ago so not going into too much detail here) but I was really surprised when I looked at the ad results. By FAR the most leads generated came from Zillow, and the only qualified leads came from Zillow, the actual new tenants came from Zillow. The breakdown: CL- 9, Zillow - 36 Trulia - 5, Hot Pads -6, Zumper - 3. The winner: Zillow.
The market is just outside of Boston, rent = $1500. Most, but not all, of the CL inquiries came from people using some sort of voucher or a request from their caseworker to use a voucher. Most of the way I structured the listings and screening info I gleaned from BP in the last few months.
The way we handled the screening was that I did all of the references, 100% of the contact and set up appointments where my relative actually did the showing. We had 4 actual showings before offering a lease to a qualified couple. (The three couples before them self eliminated for one reason or another - this couple made it to the final round, income, references, credit scores, all lined up.) This process took just over 3 weeks.
The thing I like about email contact is that absolutely everything is documented. I am not tied up on the phone, I can "work" wherever I am, even at a noisy volleyball game.
Good luck with your rentals, and the best thing I can suggest is to do a search on BP for every subject/title you can think of relative to screening tenants, that will help even more than where to advertise - my opinion.