I am also looking to adopt a dog, and found Petfinder to be a great tool.
Most dogs are in Rescue Orgs and/or foster homes, and the good ones make sure you get a vet checked, vaccinated, house trained and many times microchipped pet. They will ask you many question to make sure you are a serious candidate, and they will call your vet too. I was just approved and I am waiting for them to get me an appointment to go meet my future new dog, a 9 month old Cockapoo
I too went the Pound way before looking in Petfinder, but I have 1 child, 3 cats and a boxer, so I really need to know at least some about the dog's background , but unfortunately that's almost never available in the pounds.
The good thing, though, is that many of the dogs placed on Rescue orgs and foster homes were saved from kill shelters, so yes, you are saving a life even if you don't adopt directly from the pound.