Welcome to CF!
the amount I usually charge in my shop is 60-80 US an hour for labor + the parts that may be needed. But for in home calls it's 95-120 Us an hour (i only charge 120 when im setting up a network). also make sure you are properly certified or people will not want you to work on their comps. it would be a good thing to at least be A+ and MCSE certified for comp. repair, and Network comptia certified for networking.