I have had 9 hamsters over a course of 8 years...you have to keep the room warm in the winter and room temp in the summer...which can be difficult, but if you don't have a heater you can put a heating pad under their cage or a lamp, as long as they are warm

How big they can get: A couple inches, depnding on what breed

Best breed for beginner: if you think you can handle a dwarf hamster, go with one, but they are quick, and have mood swings, teddy bear hamsters are
best for beginners, hold them about 2 days after you get it so it becomes used to the cage and you don't scare it to death when you go to get it

How old they get: My last hamster that died last month was 4. 4 is about the maximum age, but i had one that lived to 6 under extremely good care, plenty of excersise, being held, sleep, fresh food and water and weekly cage cleanings, but it was VERY difficult, normal hamster life span, 2-3 years

What exactly do they eat: lettuce, but it is tasteless to them, don't let anyone tell you it can kill them because it can not kill them, it has vitamins in it. Rabbit food pellets, sunflower seeds, you can but bags of mixed food for them and such, there are yogie drops(which taste good), wafers, and a stick that goes on the side of the cage it is a compact of food all mushed together with honey...they tend to like those, cheese, they need vitamins, and you can get that for them

vet care: go to an exotic animal vet because normal vets don't normally treat hamsters, but they don't normally need a vet, you can get them wet tail medications. Wet tail is deadly, so when you get the drops, put it in their water every time you change it and they should be fine

obediance: you CAN train hamsters. my hamster would go around the room and not run away, recomend a clicker for that, so when they are supposed to go back in the cage you click it to return...i taught my hamster to walk on a leash, she could go in a little litter box i made her out of an old ring holder so i could clean her cage easier, but that took about 9-10 week ends....

cages and other things to know...: Never put a male or a female in the same cage unless you are planning on breeding them, females will get territorial and kill or fight with other females, same with males, but some are different and you can put two of the same gender in the same cage. Change the bedding 1 time a week and food when the bowl is empty and i reccomend give them water daily.Hold them after 2 days of them being in the cage (48 hours), hold them regularly, big cages are good, tubes and tunnels are great things for hamsters and they enjoy them. Wire cages, no aquariams, that;s ot good for them. If you do keep them in an aquariam you should put a piece of wood from a pet store in it because with the bars they can chew down and keep their teeth short. If their teeth overgrow it is either because they have nothing to chew on or they are in an aquarium. Even though the biting on the wires is annoying, it is perfectly healthy. They tend to store their food in their mouth for a night time snack. Balls to run in or wheels are a good source of excersise. Hamsters are nocturnal, they only sleep in the morning.

Any other questions?