How would I go about becoming a beekeeper?

I live on five acres and most of those acres are cover by flowers of some sort. There are three (known) bee hives. I think it might be interesting to be a beekeeper. It might fun and I could make some extra money selling honey. Maybe I could also help increase the dwindling bee population.

Where could I get equipment? How much would that cost? How much money could I make? How would I even get started?