I'm not super familiar with the Charleston Market but I feel that the rental market is on the rise in West Virginia as a whole. @Peter Tu is a local agent in the Charleston area and could give you specific information that could be of interest. In general, rentals are a great place to start though.
What are the conditions of the homes that you are looking at ? Will you have to do any work before a tenant is placed, or are you looking for something turn-key? These are important questions because renovations can quickly eat away at your budget especially if you don't have a trustworthy contractor. Also, don't stress over making your rental immaculate UNLESS you are in an area where new fixtures, flooring, etc are necessary for the price point because it's a good chance your tenants are going to F*** it up anyway lol or put more nicely not treat your things with the same care as you would.
Feel free to reach out if you have any more questions or curious about the Beckley market!