I used Pedigree's website. They have a find a dog questionnaire that works really well. It asks a bunch of questions to help you narrow down what breed/ size would suit you and your family. It will give you the option of finding out more of the particular breed so you know what you're getting into. Then you can go searching for the real thing with either a breeder or a shelter. The two dogs I have now started this way and they suit our family.