In my area the rates are from $50 to $160 an hour, i guess the guys on the lower end are part time or doing it for a hobby, the upper end is most of the service companies in the area, so i would guess somewhere in the middle would be average.
To establish a rate, you need to know all your overhead, and operating expenses, then add in a nice profit, if you look at what others charge, they may be loosing money, or making little, or no profit, not a good way to start off.
If you search this site, you will find many discussions on estimating software.