Figure $100 to $200 per month for gas and electric, higher if the home is all electric. Things that affect average utilities are:

square footage;
energy efficiency of home's insulation;
energy efficiency of air conditioning heating unit.

If you are looking at buying in Sacramento, you can get an FHA energy efficiency loan to upgrade things that will help the home's energy efficiency such as insulation, air conditioning, windows, etc.

If you have an address in mind, call the utility companies and ask what the average bill is for that address.

SMUD (888)742-7683
PG&E (800)743-5000

Don't forget trash, sewer and water from the city or county. If you are looking at Carmichael, call the County of Sacramento at (916)875-5555 and ask what the charges are.

I hope this helps.