I breed mice. Very easy and kinda fun really.

Buy all your breeding stock at the same time because introducing new adult mice to each other can be disastrous (they're little murderers)

One male can be kept with as many as 9 or so females. Aquariums are alright, but lab style rodent cages or wire cages are better as more ventilation is there.

I feed mine high quality dog food (Nutro brand Lite variety and Authority adult lite) and a mixture of puffed rice/wheat, cheerios, tri color pasta, and raw oats.