You're going to need some type of power generation, so something like a generator (which you need to refuel every so often) or something more permanent like solar or wind power.
Since you're not on the power grid, you're obviously not on any Cable Internet grid either, so you'll have to deal with either satellite or cell phone tethering. I think for long term solutions, satellite is probably the best option. For short term usage, you should probably contact your cell provider about tethering and additional costs (if any).
-Wolf sends