If they are about the size of salt grains then it is a disease called ICH. There is an article on diseases in the beginner forum that covers this. Here is a link. HTH
Any ich med at your LFS should be fine. One is called ich guard, a jungle product. Just remember to take out the carbon from your filter while using meds, if you have carbon. HTH
Straight into the tank. All other fish now have the potential to be infected and so do live plants. If the carbon is more than week old, chances are it's already done most of it's job and now is safe to use with the meds.