If your going to use solar panels off the grid then you better bring your wallet.
The problem is you need a place to store the energy for when the suns not shining. Batteries are expensive but probably most often used today. You would also need an inverter to convert the solar panels DC current to usable AC current. Oh and if your using batteries then you also need a charge controller so you don't fuck up your expensive batteries. 250W solar panels $300ea, $300 inverter, $300 charge controller, 12V deep cycle batteries $150ea, etc. You would need to do a load demand calculation to find out how many watts of electricity you need but you can do the math. Generally 3-4kW is sufficient for lighting, receptacles, electronics, and small wattage appliances. Heating and cooking would probably be done with wood or gas. A 4kW system could produce somewhere in the range of 5-7 MWH/year depending on location.
I hope I can live off the grid someday but I'm not at that point yet and don't have the money right now. Maybe when fuel cells get cheaper, then off grid systems may be more affordable.