How To Build a Composter... For those of us who haven't a clue!

Why spend money on fertilizer and soil... when you can pretty much make it yourself!  Just think that now you have something to do with all those veggie peelings and grass clippings that you have been tossing into the trash anyway!
 
Okay, I have never really built anything in my life, but this project seems like something I could handle.  I am including the url HERE for step by step instructions!!

If I can do it myself and I'm pretty sure that I can pull it offf.. why would I want to head to a store and buy one??