Just get a plastic ziplock baggie to put over the dish receiver part and use RainX to coat the dish with so it repells water. Otherwise when it rains you will lose the signal. You might still lose the signal in a snowstorm or heavy rain that blocks the sky.
Signal quality varies depending on how you point your dish. Get at least 80% signal strength before you lock in your dish position. Over 80% looks better than digital cable to me.
You need a satellite receiver for each TV in your home, and a remote control as well. They should provide those, but make sure you get the same model for every TV in the house, we got two different models and using one is different from another. One is a Huges and the other a RCA. Different remotes, different menus, but same programming.
Dish was going to buy out DirecTV, not sure if that is going to happen. We got DirecTV and pay $35/Month for 150 channels and two receivers. They charge $30 for the programming and $5 for each extra receiver. Our local cable TV serivce costs almost twice as much with only 80 channels on their digital network. It used to be $85 a month for digital cable, but they got more competitive and lowered the cost to $65 because satellite companies were undercutting them in our area. The local cable company also wants to bundle a cable modem and Internet access as part of the package, but they still are not as cheap as my DSL and Satellite services.