How do I teach my one year old golden retreiver to walk properly?

[Rebecca C]

I recently adopted a 1yr old golden retriever from a home with three other dogs in it. The dog has never been walked on a leash before, and its obvious. The dog runs out into the middle of the road when a car comes, he manages to slip his collar whenever he sees another dog and runs away from me. I bought a retractable leash hoping this would help him, but no such luck. Because he is so poorly behaved I continually have to cut our walks short, I would love to take him for a nice long walk, but it seems that everywhere in my neighborhood there are dogs around and he goes berserk when he sees them.Any help would be greatly appreciated. Thanks in advance