Yay! A C&C cage! I was hoping you would have that, so then I wouldn't have to lecture (well, not really) another person on how petstore cages are too small!

Are your guinea pigs long haired or short haired? If they are long haired, you need to comb their fur out everyday. If they are short haired, you need to brush them every day with a soft baby brush or dog brush when they shed; in the spring and summer.

Guinea pigs are tough to toilet train, try to figure out which corners or places in the cage they are using as their toilet, and then put a litter box there. Also, put some of their soiled bedding in the litter box to help them get what they're supposed to do.