For your hamster to be comfortable, his cage will need to be at least 20" by 10" or larger. The cage will also need to be escape proof (hamsters are amateur escape artists), and easy to clean. When you're choosing your cage, keep in mind that hamsters can easily squeeze through small places and chew through plastic. A good cage like Habitrail Twist should do the trick.
Get a good aspen bedding like Planet Petco Aspen Wood Bedding for your hamsters cage. Avoid cedar and pine bedding, however, you can also use newspaper or fiber-based bedding if they better suit your hamster's needs. For nesting materials, tissue or toilet paper should do the trick. Avoid cotton nesting material frequently found at pet stores, it's unnecessary, and it can cause health problems for your hamster if eaten.
Food And Water
Your hamster will need a good, clean food and water area with fresh water and good quality food. For a food dish, find a shallow, small, but heavy bowl that can't easily be tipped. Avoid using bowls for water, they can be tipped or dirtied far too easily. Use a hanging water bottle like Super Pet Wide Fill Water Bottle instead to keep water clean and full.
Hamsters love to run, and need plenty of exercise to stay healthy. To keep your hamster exercised in his cage, buy a nice exercise wheel like Super Pet Comfort Exercise Wheel, and choose the largest one you can find. The wheel will need a solid surface and no cross supports that can catch your hamsters leg and cause injury. The best wheel will run quietly, and attach to the side of your hamsters cage.
Your hamster will also need a variety of toys and things to chew and climb on. Chewing sticks like Vo-Toys Hamster Chew Sticks will help with this. Also consider adding tubing and levels for your hamster to run and climb on.
Your hamster will want a private place to sleep, so consider putting a small home or hideaway in his cage. You can use a cardboard or plastic box, or a coconut shell for this purpose. If you're not a "do it yourself" type of person, you could always buy a small hamster house like Super Pet Woodland Get-A-Way Hamster House to do the trick.
With these things, your hamster will be happy and healthy in his new home. Take good care of your hamster, and have fun!