I highly recommend Nikki's Collar Club. Nikki provided obedience training classes for our rescue, Wally, at 5 months. She was extremely flexible in making sure to get started right away and completed the classes in six weeks. She came to our home for them, gave us detailed weekly "homework," and to this day (at 10 months) Wally gets compliments on how well-behaved he is!
Since then, Wally has learned to come when called, stay, leave it, down and other more fun tricks :)
She also is our go-to pet-sitter if we need to go out of town. I am comforted knowing that Wally is in good hands when we need to stay overnight somewhere, and he always has another dog to play with. And better yet, her rates are very reasonable.