1. Get Him Used To A Leash And Collar
Before taking your dog out on a leash for the first time, get him used to the weight of a leash and collar. Start by attaching the collar. While you're waiting for him to get used to the weight of it, play with him and keep him distracted. Once he seems used to his collar, attach the leash. Supervise him as he gets used to the leash, let him play with it and drag it around until he seems accustomed to it.
2. Let Him Play
Now that your dog is used to the weight of a leash and collar, it's time to let him play. Be sure that you incorporate playtime daily with your dog, before you begin leash training. This will allow your dog to alleviate any pent up energy, so he'll be a little more manageable when you're ready to begin training.
3. Start At Home
When you're finally ready to begin leash training, start at home in your own backyard. This will help eliminate any distractions so your dog can stay focused on you. Keep these training sessions short at first, 15-20 minutes at most. Try to keep these sessions fun, so your dog will have positive associations with walking in the future.
4. Let Him Follow
5. Start And Stop (With Treats)
The next step is to get your dog to stay by your side. Continue to stay at home for the first couple training sessions, and employ a start and stop technique. Whenever your dog begins to pull ahead, stop walking. Be sure that you don't pull or yank on the leash, as it can damage your dog's throat. Instead, give him a verbal command as you stop, and wait for him to come to you. Once he does, praise him and reward him with a treat. Start walking until he begins to pull again, and then repeat. Once your dog is consistently staying at your side in your own back yard, feel free to move on to the sidewalks and employ the same technique.
After following these steps, your dog should be basically leash trained. At the very least, your walks with him will be a little more pleasant. Have fun, and enjoy walking and jogging with your newly trained dog!