Startup a Computer Business?

RapDes asks: "I've been a long time Slashdot reader and I've had years of experience working as a computer admin (secondary to my main job title) at a few different companies. I'm constantly being asked by my friends to take a look at their PC's to fix problems or to setup home networks (like I'm sure most of you fellow Slashdot readers are, as well). Anyway, I've decided that I'd like to make a little extra beer money on the side by starting up my own computer service/upgrade/repair business. I'm looking for any input from the readers who've already been down this road. How much do I charge? What should I be focusing on, hardware upgrades? Virus and spyware removal? Home networking? Any advice would be greatly appreciated."