I've been lucky so far and have never had any troubles with disease or parasites since I started my hives 4 years ago. I did buy a starter kit from Mann Lake that included CheckMite+, Teramyicin Patties, and menthol crystals I believe. After reading the precautions on CheckMite+ I decided against using it unless absolutely neccesary, that stuff is quite toxic. The Teramyicin Patties seemed like a good idea except that the patties are moist and I would think that that alone would reduce their shelf life, if you get these you may want to refrigerate or freeze them. A Teramycin powder may be better in the long run.
I did purchase a bag of artificial pollen from Mann Lake a well. I really like that stuff and feed my bees with it in early spring to get them to build up stronger earlier. With the artificial pollen and some Teramyicin powder you can make your own terra patties.