Originally Posted by
wendy
I think you're setting yourself up for a potential disaster if you select your dog based on "how it looks" (especially from one of those icky photos on petfinder), or how it behaves in a shelter environment- many dogs act very abnormally in a shelter, and well, you'll hear all kinds of stories about how the dog who seemed wonderful in the shelter turned into something totally different in the home environment, often with tragic results, or at least with less than desirable results.
Far better to be very honest with yourself about your capabilities for exercise, training, attention, and grooming, and then extensively research breeds and bloodlines within breeds. And then be honest with the breeders about yourself so they can help match you with an appropriate bloodline and puppy.
If you're going the rescue route, you should be very honest with the rescue about yourself so they can match you with an appropriate dog, based on their foster people's knowledge of the dogs. If you're doing the shelter dog route, at least learn how to perform a basic temperament test and bring a couple of experienced people with you to help you evaluate the dogs for suitability.
Basically the best matches are made when someone who knows the dog better than you do picks the dog for you after you explain your needs/capabilities.