Grooming
While guinea pigs don't normally need to bathed on a regular basis, they do benefit from a good brushing -- especially during shedding season. A good brush with soft bristles is very effective for grabbing loose hair. For short-haired piggies, a flea comb -- used gently -- can be more effective than a petting brush.

For shampoo, pick something made for bunnies and/or guinea pigs. Many vets also recommend good ol' fashioned baby shampoo.
Guinea Pig Petting BrushBunny Bath Shampoo, 6 OZFlea Comb - Small - 3.75 in.
Guinea Pig Petting Brush
$3.40
Bunny Bath Shampoo, 6 OZ
$4.32
Flea Comb - Small - 3.75 in.
$3.51
Clip N Trim CritterSuper Pet Hand Sanitizer Gel 4 oz
Clip N Trim Critter
$3.40
Super Pet Hand Sanitizer Gel 4 oz
$3.90