Guy, as far as ice and snow, do NOT use cooking sprays or greases. While they work the first few times, they like to attract dirt and dust which will degrade the signal. The best thing is RainX applied every few weeks. When you apply it, apply it like you would a car windshield, but be careful not to push on the dish so hard that it throws it off balance. Also, when applying make sure you remove power from the modem so your not getting blasted with radiation from the transmitter.
Best things to use for snow prevention.
1: Regular coatings of Rain-X this will help the snow slide off.
2: A soft bristle broom to help sweep the sheet of ice off if Rain-X was applied...
3: A good quality super-soaker or sprayer full of Windshield De-Icer if the ice is already caked onto the dish, this will help break it up and let it slide off easily.
4: Dish HEATERS are NOT recommended as they can interfear with your transmission signal.
5: Greases are NOT recommended due to dirt build up.
If you live in an area where you MUST use a dish heater, install the heater on the back side of the dish, and along the arm of the dish, be aware while on it can interfear with the signal, so use it only to help clear the dish, or keep snow/ice from building up during a storm.