Well, first off, the most important things guinea pigs NEED is vitamin C. They need a good daily dose of it each day. Oranges and about 1-2 drops of liquid supplement found at pet stores is enough for them. They need exercise regularly, and a nice spacial cage. Oh, and also, don't get ONE because guinea pigs are social creatures that like to have company. See if your local humane society has a pair of guinea pigs up for adoption, too. Give your guinea pigs fresh water changes about once a week in a sipper tube for them, as a water bowl gets filled with shavings, etc. They love vegetables and give them this every day. Timothy hay is good for older guinea pigs, whereas alfalfa hay is for younger guinea pigs. Last, give 'em lots of LOVE!