Determining Market Rental

[Eric Graig]

I am looking at some properties to purchase for either AirBNB or long term rentals. What is the best way to determine the going rate for rentals? Also, is it better, worse, or does it not make a difference whether I purchase a property with existing tenants than one that I would be converting to a rental? Finally, what kind of interest rates can I expect for an investment property. I have good credit and can offer a substantial down payment.

Thanks much.