How to stain concrete floor

We built our house in 2001. A few years ago we ripped up all the carpet in the entry, halls, office and living room and put down wood floors.

But believe it or not, we still have the original carpet in the bedrooms and am ready to replace them. My wife is diggin the stained concrete look but I dont know anything about it. Seems easy/cheap... just rip up the carpet and "paint" the floor with a stain...

But im sure there is more to it to make it look nice. Was thinking of attempting it in a small bedroom like my sons first...

looking for tips, thoughts, ideas....