A wire cage with a solid plastic base is ideal for mice, they should have enough room to stand upright. Provide a nest box and suitable nesting/bedding material. Mice can squeeze through tiny gaps so make sure the housing is escape proof. Keep indoors away from draughts, direct sunlight and other pets. Clean out once a week and always keep a bit of the old bedding for familiarity.
Mice naturally live in groups so keep in single-sex pairs or groups, preferably from the same litter. Do not mix with other species of rodent, such as rats, as they will fight.