I suggest the following: (these are basic suggestions based on my experiences with dogs myself and friends with dogs)
1st - Decide what you want out of the dog, and how it will fit into your lifestyle. (big dogs need just as much exercise as a small dog, and vice-versa...just small dogs don't knock the furniture over when they are overly exuberant ..they all get hyper though..just one can cause more extensive chaos then the other.
Small dogs tend to get nippy, yappy, and destructive when they are under-exercised, large dogs tend to get destructive, barky, and in worse case scenario, aggressive..keep this in mind.) Large dogs with large tails also tend to knock low-level items on tables off into the floor, also keep this in mind lol.
2nd - Decide if this is going to be an inside or outside animal. Inside/out rarely works..they stink very badly after going outside and staying indefinitely (over an hour or so) and it is also easier for them to subsequently ruin your carpets, floors, walls, clothes, and furniture. Dogs really do not need to be bathed more then once a month (if that, less is best)..or else you run the risk of them getting dry skin which = dandruff, which is sometimes very hard to correct once it gets started.
3rd - Decide if you want a puppy, sub adult, or adult animal.
* Puppies (meaning under 8 months) need a minimum of 6 hours contact a day (meaning someone who works 8-10 hours a day isn't going to have time for a puppy), or you run the risk of them developing social misbehaviors (barking, digging, destructiveness, ect). They also need to be socialized at least 4 times a week, outside the home..or they can become territorial and non-friendly to company. Also take more diligence to train, as their attention span is short (like children). They also cost a great deal more in the front run, due to vaccinations and vet visits during their first 6 months of life. They require a more diligent feeding schedule, as they need to eat 3-4 times a day for the first 3 months of their lives as well.
* Sub-Adults (meaning a dog over 8 months but under 2 years) only need about 3-4 hours of contact a day, to keep them from developing the same bad habits as a puppy (keep in mind the younger the dog the more contact time they require). They still need the socialization away from the home as well though, and it needs to be at least 3 times a week. These dogs are generally already housebroken and can (or cannot) have decent house manners. These are generally the easiest to train (or re-train) to your liking. Require minimal vet care, as they only require yearly vaccinations after 6 months of age. Their feeding schedule drops from 3-4 times a day to twice a day.
* Adults (meaning over 2 years) need at least 1-2 hours of contact a day, although they can withstand less..due to the fact most are happy to lounge about all day, so long as they are not locked in a crate for extended periods of time, mind you. Socialization is still crucial for them, although generally they are already set in how they are going to react to other people (key motive when selecting an adult animal). They can be harder to train, if not trained already, and if not properly socialized this can require more time then a puppy to develop. They require minimal vet care, as they only require yearly vaccinations. Their feeding schedule is also minimal, being 2 times a day (although some choose to feed only feed 1 meal a day, certain large breeds (mainly the ones with deep chest cavities) require the amount to be divided into 2 meals to stave off a condition called Bloat...ie. Dobermans, Giant Schnauzers, Great Danes, ect).
4th - Decide if you are comfortable with an animal running loose in your house while you are away, or if it will be crated. Large dogs do not bode well when left cramped up in a crate for extended periods of time...as all they can do is lay in one position. Smaller dogs fare much better in crate situations in those cases.
5th - Decide what dogs you are allergic too before buying. Chances are if you are allergic to cats you may be allergic to some types of dogs, long hair/heavy shedding dogs in particular (German Shepherds, Golden Retrievers, Huskies, Collies, Pekinese, Shiitzu's (lol stupid curse control making me mis-spell things lol), Pomeranians, ect). Grooming also plays into a major part here as well. If you don't/won't have the time to groom EVERY day you will either end up having one raggedy looking dog...or it will always be shaved.
6th - Deciding on a certain breed should also bring to mind future vet bills. Certain breeds bring to the table certain illnesses that they can acquire later in life. Pet insurance is a great necessity for these breeds, to help offset the future costs to your wallet. When buying a puppy you really need to make sure you know what illnesses are common for that breed and check with your breeder to see if the parents and grandparents of the puppy you are looking at have been tested for these genetics conditions (they have medical tests to determine the probability of all the genetic conditions for each breed..not all breeders test though..BE AWARE!). But keep in mind, just because the relatives tested clean...your new puppy can still be harboring the condition...passed down along the lines...and it can crop up later in life without warning.
7th - Decide if you want to adopt from a Breed-Specific Rescue or buy a puppy from a breeder. Both have their good and bad sides.
* Buying from a breeder - You get papers, you can research the genealogy of your puppy, you can teach your puppy your ways, you can make sure the puppy is socialized. Puppies are loud, obnoxious, time consuming, get sick, need frequent trips to the vet, have to be housebroken, chew on things, ect.
Breeder checklist:
Does the breeder own/have both parents?
Have both parents been temperment tested?
Have both the parents and grandparents been health tested for all genetic problems for that breed?
If not, have at least the parents been tested?
Are the parents papers readily available for customer viewing?
Does the breeder have the puppies blue slips ready for viewing?
Are both parents on premises, and if so are they both friendly and in good health?
Are all puppies friendly, healthy, and active? (look for pale gums, runny noses, cruddy eyes)
Does the breeder have documentation from a veterinarian that they (parents and puppies) are current on vaccinations?
Does the breeder demand that you sign paperwork stating if the puppy is "pet quality" that you will have the animal fixed, that it will not be left to run the streets else the owner risks the animal being taken back, that if you are unhappy with the puppy's temperment or health status, or unable to continue to provide a home, that the breeder will re-home/take back the puppy, and that if the animal is found in ill-keeping that the animal will be taken back?
**this is why you pay so much for a quaility purebred dog; because of the extensive testing that *is supposed* to take place before the breeding. The purpose is to make every effort possible so that the puppies are gentically sound. If the breeder does not offer atleast 1/2 of the major testing needed...I suggest taking your search elsewhere!
* Adopting from a Breed-Specific Rescue - You do not get papers, you cannot research genealogy every time (although sometimes it is possible), you generally have to re-teach most dogs to fit your lifestyle and training wants, usually needs extensive socialization (due to being in the rescue centers for extended periods of time). You normally are adopting sub-adult to adult dogs, they are already housebroken, they do not chew things up, they are usually somewhat socialized, you know what their temperment is, they do not need frequent vet visits, you generally know if they have health problems up front, and you save a dog from a life (or death) behind bars.
Just always remember (or remind) that picking out a dog is a life-long commitment (not your life..THEIRS) and making the best purchases you can will result in a good life for both you and the dog.
If you need any help picking out a breed...PM me your wants/needs...I know alot about several different breeds that I could suggest (everyone I know has had me help assist in picking out their dogs/cats lol).