The akc.org website has lots of information for dog owners, including how to choose the right breed for your lifestyle, how to care for your dog, etc. The chihuahuaclubofamerica.com also has information on caring for a chihuahua.
Please read the following article if you are planning to purchase a chihuahua puppy:
Hypoglycemia
Before your pup comes home, go to your pet supply store and buy a tube of "Nutri-cal". This could save your pup's life. Hypoglycemia is low blood sugar. It can occur if a puppy has gone too long between meals, has gotten chilled, or is stressed. It is common in small breed puppies and is life threatening. Your puppy could die of not treated for it quickly. A chihuahua puppy should always have access to food and must be monitored to make sure that he/she is eating. The pup should always be kept warm, just like you would with a human baby, and should be watched closely after periods of stress, such as the first day in a new home, shipping, or first trip to the vet, and after periods of prolonged activity. Here are some signs of hypoglycemia: weakness, listlessness, uncoordinated (acting as if drunk), blue or gray tinge to the ears, gums or skin, cold to the touch, confusion, disorientation, and/or unusual drowsiness. Left untreated, the dog may go into seizures, and/or unconsciousness and may die. If you see any of the above signs, first administer a supplement such as Nutrical (preferable) or honey, corn syrup, sugar, etc. Dab it on the pups' gums or under the tongue. Then feed a protein-rich food, such as meat baby food or canned food. If symptoms do not improve immediately, CALL YOUR VET. If your pup perks right up and seems just fine after receiving the Nutri-cal or other sugar source plus protein food, closely monitor him/her. Do not put sugar in your chihuahua's drinking water. This will not prevent low blood sugar, and could even cause the blood sugar to spike and drop, creating the very condition you were trying to prevent.