Once you have a cage, you need something to put in it! So, first of all, you should set your cage up before bringing a new hamster home (to reduce stress). Always use a non-aromatic bedding, such as aspen or pine. Carefresh brand bedding is an excellent choice, too. It is made especially for hamsters who have sensitive skin or allergies. Never, ever use cedar shavings! I've learned the hard way on this one. It causes respiratory problems in dwarf hamsters, so don't even try it!
Also, you will need chew sticks or chew toys. These come in all forms, like wooden fruits or just sticks. Either way, you will need them for your hamster. They wear down the ever-growing incisors of dwarfs. If you don't give them chew sticks, they will chew on something else, like your brand new cage!
Offer your hamster toilet paper pieces (unscented). Their natural instincts kick in and they go bananas making nests. Never use cotton BedFluff. It causes hamsters to become tangled and get hurt. Just stay away. They like extra bedding and toilet paper, anyway, to make a big, warm nest.
Always make sure all of the compartments, add-ons, and doors on the cage are tight and secure. Also, try to avoid areas that are accessed easily by other household pets. You'd be surprised how much dogs love to watch (and probably eat) hamsters. Cats, too. If you have an aquarium cage, a good investment would be clip-on cover locks. They work very well by keeping children and pets out of the way. All of my hamsters are kept in my room, but I allow the animals to go in there periodically, when I'm watching. Otherwise, I close the door because I've had some close calls!
Be sure to check your water bottle each day. Sometimes, the hamsters pile bedding underneath it, causing the bottle to empty into the bedding. If this happens, remove the wet bedding. If the bedding is completely soaked, just replace all of it.
You should probably change your hamster's food every 24 hours. Just empty the uneaten food into the trash and refill the bowl.
And lastly, keep an eye on your hamster. You never know when one could come down sick or become injured. Observe them each day to make sure they're acting like their normal self.
If you follow these simple guidelines, your hamster will be safe and happy.