Welcome to BYC and the world of chickens! To learn more about chickens and get some good tips, go to the Learning Center on this website, search for information on the internet, and get some good books. There's a lot of information out there about sucessfully raising chickens, and the more you read/learn, the better off you will be with your birds.
However, here are a few tips and basic information on the most important things in keeping chickens:
Housing
Chickens need secure housing, as they are susceptible to predator attacks. This includes having a coop with secure latches and having a run/outside area that a predator can't dig under or get over into. Each chicken should have at least two square feet of inside coop space, and at least 10 square feet of outside space. The more time your chickens spend inside, the more space they need. If you keep laying hens, they'll need about one nest box per four hens to lay eggs in. Roosts are also appreciated by chickens, though not all birds will use them.
Bedding
Pine shavings and chopped straw are two good materials to use. Don't use cedar shavings, as they can irritate a bird's respiratory tract. Keep a 3-4 inch layer of bedding in the coop, increasing it to about 5-6 inches in the winter time.
Feeding
There are three main types of feed: Starter, grower, and layer. Starter feed is for young chicks, grower is for older birds (often, Starter and Grower are combined into Starter/Grower feed), and layer feed is for adult laying hens (or pullets close to laying age). Don't feed layer feed to young chicks, as it contains too much calcium for them.
Feed comes in mash, pellets, and crumbles. Mash is very finely ground, and can be wasted by chickens. Pellets are compressed mash, and usually work well. However, you'll run into chickens that don't like pellets, and pellets may be too big for smaller birds like bantams. Crumbles are my favorite, as they are easy for young birds to eat. Crumbles are broken up pellets.
A large fowl chicken will eat about 1/4 pound of feed a day. Keep the feeder full at all times. Most people use a tube-type (also called a "hopper type" feeder) feeder. Trough feeders are another choice, but chickens often waste more when using them. Chickens love to use their beak to "bill out" feed, so keep feeders at the level of the chicken's backs. This will make it harder for them to "bill out"
Water
Like all animals, chickens need a supply of fresh, clean water. There are many types of waters and watering systems. Fount type waterers are common, and work well. There are also cup waterers and nipple waterers, as well as trough waterers. Change water whenever it becoems dirty, which is often every day.
Diseases
Even if you do everything right, chickens always seem to get some sort of disease or injury at some point. Keep some supplies on hand to treat sick birds, and read up on poultry diseases. Its good to have these items around:
A dewormer (like Safeguard or Valbazen)
Electrolytes, vitamins, and probiotics
Broad spectrum antibiotics (Duramycin, Terramycin, Tylan50, and Tetroxy HCA-280 are all good ones)
Needles and small syringes for injecting
BlueKote antiseptic spray for wounds
Antibiiotic ointment without "caine" ingredients
Corid (a Coccidostat)
Nail trimmers for dogs and cats (for trimming long toenails)
Human nail clippers (for trimming long beaks)
Hope this helps!