Having a pet means that you are responsible for the wellbeing of that animal 365 days a year for it's lifetime, not just when it is convenient!
For the proper way to look after small animals such as hamsters, guinea pigs, rabbitts, gerbils, etc... , please click here
The following will (not listed in order of importance)
FEEDING
For cats and dogs it is important that you feed them a good quality cat or dog food. Most commercial brands will provide the proper balance of vitamins and nutrients that they need to maintain a healthy and active life. You should not feed your pet table scraps because they do not necessarily contain the elements that your pet needs, and may contain some things that are even harmful. It is also essential that your pet have access to clean, fresh water,
at all times! Adult cats and dogs should not be given milk
on a regular basis; milk is okay as an occasional treat but too much can cause intestinal problems. You should also be careful not to under or overfeed your pet because being overweight causes undue stress on their muscles, joints, heart and other organs - listen to your vet and/or follow the pet food manufacturer's instructions (located on the label).
Ideally, dogs should be walked at least twice daily and should wear a collar with an I.D. tag just in case they get away from you. Check to see if there are any "dog-parks" in your community where your dog can be allowed to run and play wihout a leash. Most love to play catch with a ball, stick, or frisbee!
Cats should be allowed access to the outdoors (but not made to stay outside all the time), so they can enjoy the fresh air, sunshine, and a romp in the grass. Like dogs, cats should also have a collar with an I.D tag on it that states their name and your phone number. A collar with a "quick-release" clasp can save your cat's life as it will open if it gets hooked on something as your cat explores it's environs - a regular collar may strangle your beloved friend! 
Catnip is a good way to exercise your cat but , like all good things, it should be used sparingly.
If your dog is kept outdoors, make sure that it has adequate shelter from the cold, rain, snow, wind, and sun. Never muzzle your dog on hot days because he/she will not be able to pant to get rid of excess heat and will be unable to drink water to stay hydrated, and never leave a dog (or a cat) in a hot car! Remember, it is vital that your dog always have plenty of fresh water.
If you choose to keep your cat indoors, you should train it to use a scratching-post 
so that it doesn't damage your furniture. Even if your cat is an "indoor-cat", you should not have it de-clawed because if it does happen to escape and get outside, it will have no way of defending itself if it is attacked by another animal, and will not even be able to climb a tree to escape.
Your cat's litter box should be cleared of waste at least once per day and should be cleaned and dissinfected at least once per week. We reccomend that you have one litter box for every cat in your family, and that you use litter that is made from ground corn-cobs; it clumps as well as any other litter and is less damaging to the environment as it is completely bio-degradable; it is also safe to flush into most septic systems.
Your pet may not be showing any signs of illness or disease, but you should still take it to the vet for a check-up at least once per year because your vet can spot symptoms that may not be evident to the average pet owner. Note: Click here for first aid, and here for dental care
This is arguably one of the most important things that you can give your pet. Pets thrive in a loving home and you will find that they return it unconditionally. They will absorb every ounce of love you give them, multiply it by ten in their warm, furry, hearts, and radiate it back to you and your family.
Note:Young children should be supervised with a new pet until you are certain that they know how to be gentle and respectful of it.