I would like to ask everyone to consider adopting an adult dog or cat. Many available dogs are over 18 months, and will be euthanized more quickly than puppies. A fear of high veterinary bills prevents many people from considering adult pets. Sometimes this is the case and sometimes it isn't, but puppies often have more expensive problems while they are young.
Choosing a pet requires input from all family members, as well as careful, complete research. If taking care of the pet is a family responsibility, one adult should still be designated to make sure that the pet is taken care of. 
These are some general guidelines, but every dog is different, and you need to make judgements based on the individual pet. (Just beware of pets with a reputation for certain behavior.) It is important to consider the ages of family members when selecting a dog. Children under 7 usually aren't compatible with dogs under 5 months and/or under 15 pounds. Puppies may scratch and teethe on children, and smaller (toy) dogs can be quicker to bite when handled. A medium to large dog, over 5 months is best for children. Strong, adolescent dogs are a bad idea for families with elderly or physically challenged family members.
A new pet should be brought home during a long weekend or other time when someone will be home... but NOT over a major holiday time. Older dogs may miss previous owners but they do get over the loss and bond again. The typical time for a dog to become completely settled in a new household is 90 days.
Following are three of the best places to obtain a dog or some other pets:
Animal Shelters or local Humane Societies Most shelter animals are screened for major health and temperament problems. Purebred and mixed dogs can be adopted for a reasonable cost. Shelters often provide free initial check-up, spay/neuter surgery, or other items or services.
Private Breeders They can answer your questions and give you specific information about the breed you are considering. The prices are better than they would be at a pet shop. Contact the American Kennel Club for names and addresses of national/local breed clubs. Some important questions to ask a breeder are how many other puppies (or kittens) were in the litter, the puppy's age when seperated from it's mother, how many dogs the breeder has, and how many litters per year and different breeds of puppies the breeder deals with. Also try to find out about the breeder's overall reputation. (Those questions are credited to Pugs: A Complete Pet Owner's Manual by Phil Maggitti.)
Purebred Rescue Groups They can be found through animal shelters. Rescue Groups can inform you about the breed, and how to train. They have dogs available for a very small price, but who often need immediate medical attention.
The following sometimes turns out well:
Adopting a Stray Adopting a stray off the street, or an animal from a private owner is risky, but it can work out.
Never go to the following places to find a pet:
Pet Stores NEVER buy from commercial breeders or pet shops. Pet shop dogs usually come from puppy mills. The only instance in which to buy a shop dog (/cat, etc.) is if the breeder is available to discuss the animal with you. Be sure to ask the breeder why s/he sells their animals through a pet shop.
PUPPY MILLS Puppy mills are usually a group of small wooden or wire-mesh cages or crates where females breed continuously to produce a maximum number of puppies. The females' bodies give out around age six and then they are killed. Both the mothers and the puppies suffer from malnutrition, exposure, and lack of veterinary care. Puppies are taken from thier mothers too early, and suffer through transportation in even worse conditions. Only half of the puppies survive long enough to be distributed to stores. Cats and kittens endure the same conditions on a smaller scale. The puppies in pet shops suffer from being in small cages with no exercise or human contact. They become destructive, unsociable, bark excessively, bite constantly, are almost impossible to housebreak, and are extremely unhealthy.
However, many private breeders are respectable, and produce only a few well-raised puppies or kittens a year. They find excellent homes for the animals, and make sure they are spayed/neutered. Such breeders truly care about the animals, and there is no reason to avoid them.
