Alright, so there are several options for ick.
Like others have said, check the post on hypo. It's a pretty long process really and you have to make sure you're doing the job correctly, but it's probably the best way to make sure your fish are healthy. Usually you want to do this before you actually add them into your main tank.
Other options:
If you have a alternate tank that you can place the fish into for a while-
Hypo..
Copper..
Sometimes a fish can fight ick itself with some help. Soaking their food in garlic can help, but may not really cure the problem and the ick will still remain in the tank.
A cleaner shrimp may help to clean the fish of ick. Sometimes they will clean and sometimes they won't.
Some fish will clean parasites off of other fish. Although, it's not a great idea to introduce them into your tank because after the problem is gone, these fish will starve and die.
If you do searches for ick on this website, you'll see a ton of posts about it and possible cures.