What does Ich look like: Ich looks like a fine dusting of sugar covering all or part of the fish. The first day it may be just a few dozen spots, the next day, there are thousands of spots. It is often most visible on the fins. Ich is not one or two little white bumps on a fish.
How to cure Ich: The key to treating Ich is to act quickly, i.e. the minute you see it. If you wait a day or two, the game is often over. To do this, it is generally a good idea to keep a bottle of Ich medicine around the house. There are various brands of Ich medicine, and basically they all require you to treat the tank daily with a number of drops of the liquid medicine. You must treat the tank everyday for the whole period suggested on the bottle. This is often for a week. The treatment works because everyday some of the cysts are hatching, and you can kill that days parasites with the medicine. The life cycle of ich is about a week (faster if the water is warmer) so if you treat for a week, all the cysts will have hatched and the parasites killed. This is also why many people recommend increasing the water temperature.
As the days pass, your fish gets worse and worse and likely won't feed. It becomes a race to see if you can kill the Ich, before the ich kills your fish. As I said at the start, the key is to be prepared and act quickly at the first signs of Ich.