Get the largest cage possible, that allows for room for flight (a pet canary should never have his or her wings clipped and should be able to fly in the cage for exercise).
"Flight" type cages are the best (home built or commercial) since they are designed to provide room to move.
Remember that a long cage is better than a tall narrow one (the height is not all that important). Try to get a cage at least 24 inches long.
Watch the spacing between bars - no more than 1/2 inch.
Wire cages are best, wood or bamboo cages are too difficult to keep clean.
Perches: wood perches of varied diameter work best (3/8 to 3/4 inches). Some canary keepers alter smooth round perches by scraping them with a saw blade or utility knife, just enough make the surface slightly irregular (easier to grip and the variety may make the perches more comfortable for the canary's feet). Do not use sandpaper perch covers.
Temperature: canaries are pretty hardy and can be kept at room temperature. Keep the cage away from draughts, air conditioners and windows that receive direct sunlight (the cage and canary can get overheated).
Light: cover the cage at night, at the time the sun goes down (unless you live in an area with extremely long nights or days such as the far north). Canaries need their rest and will do best if given a light/dark cycle that approximates natural changes. Keeping them up late with artificial light is not healthy for them.
Toys: provide toys, but place them in the cage in such a way as they do not obstruct flight space. Your canary might enjoy swings, mirrors, bells, and hanging wooden or acrylic toys.
Fresh water should be available at all times.
A shallow dish of water or a special bath bought at the pet store should be provided at least 3-4 times a week for bathing.
Foods that are bad for canaries: Celery, onions, iceberg lettuce, Chinese pea pods, tomato, avocado, apple seeds, mango, chocolate, candy, mushrooms, salt, caffeine. These are very hazardous to your canary and can kill him/her. While breads, chocolate, and cake can't kill your canary, it'll make him fat.
Food that you should feed your canary include: Broccoli, corn, yams, sprouts, romaine lettuce, grated carrots, jalapeno peppers, apples (remember, no apple seeds!!!), oranges, bananas, melons, straberries, blueberries, most other fruits, honey sticks, cuttlebones (squid skeleton--not only full of calcium but keeps your canary's beak strong and healthy; your canary should have access), and one teaspoon of diced hard-boiled twice three times a week.