There are plenty of helpful folks here. My guess is that 39 is when most folks first start thinking seriously about retirement, so you're probably in good company.
Check out he FAQs for a wealth of information, then cruise around the current threads that are running.
There are people here who have earned their retirement through real estate investments. My guess is that most people here would probably suggest that you broaden your investments to include other areas as well--stocks and bonds, etc. If you have a lot of properties I suppose you could pay someone to manage them in your retirement. If you own a lot of properties and manage them yourself in your "retirement"--then you probably aren't really retired, you've just changed jobs, right?
"Freedom begins when you tell Mrs. Grundy to go fly a kite." - R. Heinlein