I'm bored

I need to grow something. I've only had one grow. It was outdoors and IMO was very successful. I'd like to try a little indoor grow. I've got some seed left from last summer that ended up being excellent weed. I've also got a spare closet. What advice would you guys give to someone who needs to do it on the cheap. My research leads me to believe that cfls will work for veg and I'll need to upgrade lighting for flowering.
What do you think the bottom line would be to try this on the cheap.