This forum is great. I am currently using Tenant Cloud to manage my 6 doors from 3 hours away. For $9 a month they provide rent payments, maintenance requests, messaging, screening, property listing and much more. I have been using them since October and have very little complaints.
One tip that I do is I make sure to only use one card for all my purchases. This is of course separate from my personal banking accounts.
I also use the same 24 hour home repair company. They service a property's AC and HVAC once a yr for $195 ($99 if you only have HVAC) and it enrolls you in their "Peace of Mind" program. It give us 24 hr service if needed without the 24 hr price. If they have to go out on holidays, nights or weekends their is no extra charge than if it were a Tuesday at 2 pm. Also if we do have them repair anything we get 10% off. They are extremely professional so the cost of having them go out verses trying to find the cheapest guy on craigslist is worth it to us. If you are in Fort Wayne, IN they are Korte Does It All.
Tenant Cloud and the 24 hr company help us manage our properties from a far pretty easily. We have only been doing it for a few months but I can say long distance land lording can be done!