Contact several breeders, not just one. When you call, have a piece of paper handy so you can take notes. Here are some questions to ask:

What do they have available? When will they be ready to go? Most states require breeders to hold puppies until they are at least 8 weeks old. If a breeder offers you a 6 week old puppy, don't take it. The puppy will have virtually NO immunity to disease, and will be susceptible to anything it's exposed to. A good breeder knows this, and would never let a puppy go at less than 8 weeks of age, even if their state law allows them to.

Will they be examined by a vet and will they have health certificates? Most states require veterinary examination of puppies prior to sale, so if a breeder says his/her puppies will not have health certificates, or at least be examined by a vet prior to sale, deal with someone else, even if you have to pay more for the puppy. NEVER buy a puppy that has not been examined by a vet, no matter what the breeder tells you or how cute the puppy is.

Where are the puppies raised? What vaccinations will the puppy receive prior to sale? Is the breeder vaccinating them, or will this be done by a vet?

Of utmost importance...
What is the breeder's guarantee and is it in writing? If the breeder will not put the guarantee in writing, go somewhere else. If the guarantee only states that the puppy is the breed represented and has been vaccinated, go somewhere else. A fair and ethical (and required by many states) guarantee should cover contagious diseases and congenital defects for a specific period of time. Read the guarantee carefully to make sure it does. If you're told your only option in the event that the puppy is diagnosed with parvo (for example) shortly after the purchase is to return the puppy, go somewhere else. What would you do if you had a puppy shipped to you with this sort of agreement, and it immediately got sick? How would you get it back to the breeder? Of course you would have to take it to your own vet, and the breeder would accept no responsibility for your vet bills, whether the puppy survived or not. If you're unclear about something in the guarantee, ask the breeder for clarification, and then have her clarify the point in writing. DO NOT assume the breeder will "do the right thing" just because she said she would. Also, make sure you understand what you're required to do to keep the guarantee in effect.

How long has the breeder been raising this kind of dog? Does the breeder own both parents of the puppies? If not, is information on the sire available? Are the puppies registered and will you be given the registration application ("puppy papers") at the time of purchase? Because my puppies are meant to be companions, they are registered with the Continental Kennel Club. Many breeders of companion dogs have switched from AKC to CKC.

Finally, ask yourself if you like the breeder. If something in his/her answers or tone of voice makes you uneasy, contact someone else. If he/she isn't familiar with the potential congenital defects associated with their breed, go somewhere else. If he/she doesn't sound very well educated, they probably don't know a whole lot about properly raising dogs, either.

• When you go look at puppies, (this is my pet peeve), please get there on time! Don't wear a knit sweater that can be picked by puppy toenails. Don't schedule visiting more than one breeder per day as this is how diseases are spread. You can carry parvo on your hands, clothes, and shoes from one place to another. Take a shower and put on fresh clothes before going to see other puppies. Ask to hold each puppy you're considering. As long as the puppies have been vaccinated, the breeder shouldn't have a problem with this. Does it feel solid and well fed? Is it clean? Is it reasonably friendly, or does it struggle in fear to be put down? Feel around the neck and the back of the ears for flea sores. The puppy should have no sores and no fleas. There should be no bald spots (possible fungus infection, flea sore, or mange.) Have the breeder open the puppy's mouth so you can check the bite - a slight underbite is acceptable in some breeds, but in many breeds it is considered an imperfection. If the puppy has an underbite, the breeder should be aware of it, the price should be reduced, and the registration should be "limited". If you're looking at poodles, ask the breeder if the puppy will be groomed before you take it home.
• If you're choosing your new puppy over the internet, ask for pictures of the litter and the parents. If the sire is not owned by the breeder, his pedigree and photo should be available. You might also request the name and phone number of the breeder's veterinarian, as a reference. The first question I would ask a breeder's vet is if the breeder has had any dogs or puppies with parvo (or any contagious disease) within the previous six months. If the breeder has a website, keep in mind it's primary function is as a marketing tool to sell puppies. This is fine, but do not be swayed by fancy graphics. Baskets of flowers and flapping angels are not an indication of a happy, healthy puppy. You want information.
• Once you've made your choice, find out what kind of food the breeder has been feeding the puppy. My puppies always go home with a sample bag of the food they've been eating. Ask when the next booster shot is due and write it down. If the puppy you choose isn't old enough to go home with you yet, keep in close contact with the breeder as your puppy matures. Email or call once a week to see how things are going, and to finalize arrangements for picking the puppy up. If you move or change your phone number or email address, notify your breeder immediately.
• The shopping list: two little separate bowls that can't be tipped over or chewed up (I like heavy ceramic), small latex squeaky toys for supervised play, stuffed animal or fuzzy-wuzzy (made for pets), Nylabone for chewing, puppy shampoo, nail clippers, blow dryer, a suitable brush and metal comb, puppy bed, wire crate or plastic carrier (not too small), newspapers (or "wee-wee pads"), and a book on the breed of dog you're getting. Rather than getting a crate or carrier, you might consider a used baby play pen. The size is good, they're easy to move or store, the puppy can see out, and they're usually pretty inexpensive at thrift stores or yard sales. Be sure to clean it before putting a puppy in it.
• When you take the puppy to your vet, take the health certificate with you so he/she can start a medical record for the puppy. Ask about heartworm preventative and at what age the vet recommends spaying or neutering. I prefer to have females done at 6-7 months, males at 8-12 months. You do not want a female puppy to have a heat cycle before being spayed. Have the vet show you the proper way to clean your puppy's ears and clip its nails.
• If you plan to use a groomer, you might want to visit a couple and observe how the dogs are handled. Make sure the place is clean and the equipment is in good condition. The best way to find a good groomer is to ask a friend who uses a groomer for their dog.
• Spend as much time with your new puppy as possible. Talk to it and let it sleep in your lap. Don't leave your new baby unattended on the couch or bed, even for a minute. Don't expect miracles with housebreaking; be patient and consistent. If you don't want the puppy to chew on something, don't leave it on the floor! Don't let the puppy have access to electric cords. Don't let young children pick the puppy up - have them sit on the floor to play with the puppy. Don't feed it different things or give it milk - you'll be sorry as you're cleaning up the mess. Don't give the puppy free run of the house until you're sure it's housebroken. The more mistakes the puppy has the opportunity to make, the more difficult housebreaking will be. Don't expose the puppy to other puppies until after he's had his third vaccination, just to be on the safe side. Don't let the puppy walk outside where other dogs have gone to the bathroom. Give the puppy time to bond with you before taking it to visit all your friends and relatives.

That's all I can think of - good luck!