Read "The Millionaire Real Estate Investor" by Gary Keller. It just came out.
It is definitely not a summer/beach read -- while it's not difficult, there are a lot of worksheets, etc., in there for you to use. But in using these sheets, you'll be able to determine exactly what type(s) of property you want, and then use that criteria to quickly buy it.
Amazon.com has a sweet deal on it - $15.36 a book!
I've been handing it out to several people who are either already investors or want to invest. They're getting a lot out of it.