If you do business work, try getting a contract in place. You'll find it may become a moving target on what work you're doing.
Working for individuals will be decent but don't expect to keep making money on it. Everyone's kid today can do some kind of computer work and thinks they know how to fix stuff.
You're better off coming up with a flat rate for select repairs. Virus removal, $50 for example. Go to Best Buy, see what they charge, and slash your prices against their pricing. They can charge that much because of overhead and because people have few places they can go these days to have computer work done. Often, it becomes cheaper to buy a new computer for $400 than to repair the older system. That has become a downfall to many of mom & pop places that used to do the work.
Moving up into supporting a business is where the money will be found though. You could even sign on to do phone support after hours for a monthly fee, or on whatever schedule you have. Find a niche, work it hard, and you'll be doing good.
Basic computer work is fine.. but don't expect it to last. Plus, get ready for the headaches that come with doing the work. You'll fix someone's computer, 3 weeks later they'll call you saying you screwed their computer up because the printer won't work now. Or they'll keep calling you thinking you'll work for free.
Always send them a bill after they've paid saying how much the work was and that it was paid in full.