axolotls get quite large (about 30 cm), they need plenty of area rather than depth of water (only about6 inches); I would say minimum 3 foot tank - they are known to bite each other so the more space you can give them the happier their lives will be. They are amazing in the fact that they can regenerate missing limbs, but if you can avoid them biting off each others limbs it would be a far happier life for them. They are carnivours, enjoying many meaty things, be careful of anything too fatty e.g beef heart; insects exoskeletons can't be digested (eg crickets) so not best for stable diets. Earthworms are considered the best food for them, though be careful where you get them in case there is an chance of them being polluted in any way. frozen bloodworm is also a good part of their diet and pieces of fish (remember they can't chew so it has to fit in their mouth.)
They should be kept in water at all times, they do not like being handled. If they are forced to become "full adults" they can come out onto land, but they don't live as long; basically they should be kept fully aquatic and are able to breed in this larval stage.
They are known to bite anything that moves near them, including fingers, and though it does not really hurt and can shock people, they have very small teeth (mainly used for gripping prey). They won't need a heater as keeping them to warm leaves them prone to diseases and lowers their life span. They do need good filtration (though not fast flowing water as they don't like it); they are messy little critters and will need good husbandry skills.
hope this helps
