I was on the fence about getting a shelter dog and to be honest I did a lot of second guessing when I got mine. There was some biting issues as well as a hard time asserting dominance. My original thread is here. http://www.ar-15.co/forums/showthread.php?t=48036 He's 9 and a lot of people, as you can see in that thread, said there was no hope for him and you can't teach an old dog new tricks, they've trained and had many dogs, bla bla bla, but obviously they can go suck one.
Asserting dominance was easy once I realized that it was best done under the right circumstances, which I definitely did not enjoy but it worked. Food aggression was easily taken care of as well as getting him used to other people.
Now, he goes everywhere with me. I take him where ever I can and he's been great. He doesn't know what a leash is anymore and I can call him off a rabbit mid chase. I don't go to work without him unless we're on the range or jumping. All the guys love him. He's still very protective though. Even after he stayed with my parents for a week, I came to pick him up and my dad gave me a hug and he was immediately between my father and I with teeth bared. There was food aggression at the beginning but now he doesn't touch his food without me giving him the word once he's sat down. I even left him at the house one day and came back 6 hours later to find him staring at a full bowl of food because some asshole left in a hurry without giving him the word.
He loves riding in the truck also. He stays in the cab and just sort of chills there.
There's a few on here who have met him and would definitely agree he's a great dog.
Don't go after a dog for a certain type of breed or any kind of status symbol. Don't be afraid of handling certain dogs like pits or rotts either.
Get a pooch that suits your personality. Don't get a husky because you like to go hiking once a month and don't get a bassett hound because you may sit down and veg on the couch for a few hours a month.
Every dog needs three things....love, exercise, and discipline. It just depends on the dog how much of each it needs and how willing and patient you are to provide those.