Breeds: There is only one domestic species of rats so no worries. There are different ear types (dumbo and top ear), there are different hair types like rex, standard, double rex and hairless. And of course different colours. But none of it matters as it doesn't make the rat. Pick out the ones that you like.

Housing: Rats cannot and should not live in aquariums. Their respiratory systems are very sensitive and the tanks do not provide adequate ventilation for them. Wire cages only.

Litter: Never ever pine. Pine is bad for all small animals. Both pine and cedar contian phenols which cause respiratory problems. Try carefresh, aspen or yesterdays news.

Food: Look for brands like mazuri rat lab blocks or harlan teklad(only found online). They cna have just about any fruits, veggies and foods just avoid sweets and fatty foods.

Other: They don't need special vitamins or anything. But expect to need the vet at least once. Remember that rats must live in groups or pairs. And do lots of research rats are more complicated to care for then say hamster or mice but once you figure it out it is easy! Check out www.goosemoose.com and www.jorats.com/forum

Good luck!