How do I start investing in R.E.?

[Marty Gold]

I am interested in purchasing a rental property at/near the beach.   Though I am open to non beach options and open to commercial as well as residential.   Can anyone give me some homework and some formulas to start my research?  I don't have a specific property in mind, but how would I know if I came across one?  I am willing to put in the time and look through many properties, but again, what should I be looking for and how do I know what a reasonable and max purchase price should be?  Thank you to anyone who can help a newbie.