Apollo hated his leash when it was on his collar and walks much better with a harness of any kind.
For leash training make them feel comfortable with the leash on before going on walks but the leash on him and let him drag it around for a week or so, when he's outside playing put the collar on and let him drag it around, after a week or so start to pick it up and walk with him, let him be in 'charge' just direct him a little where to go around your back yard and reward him. DOn't try to take him for a walk right away let him learn to like it show him that the leash means more space to see. If this doesn't work leave the leash on him and place the loop say around a door knob for a few minutes (while you watch him so that he can't hurt himself) this will teach him that tugging and going crazy doesn't get him any where, pick the leash up and try to walk with him. Using a long line at first may also be a possibility, take him to a park and let him wonder a little bit and simply turn your back walk away and ignore him, if he doesn't come to youit will give him a little tug and hopefully cause him to run towards you as you are now 25 feet away. Hope all goes well, this may take a few weeks but practice and praise encourage the best results.