have you tried clipping the leash on his collar and just letting him walk around with it attached for a while? You should let him get used to leash by clipping it on him and letting him play, walk around outside, in the house, etc with it on. Once he gets used to it and realizes it won't hurt him, then you can begin holding the other end of it and coaxing him to walk with you and understand that you're in control.
Here's a crosspost to another board I'm on, and we were just discussing different training methods. My post is the third post from the top, but it wouldn't hurt you to read the entire post! Good luck and keep us posted. If you have any additional questions, please feel free to ask! How are you training/raising your dogs?