I like Nylon snap type or the new Nylon/chain combination collar for little puppies. Put the collar on your puppy and leave it on. You must be able to put 2 fingers between the puppy neck and the collar.
You may notice that he starts scratching his neck. This is not a problem and will go away in a few minutes. Do not try the leash right away. Give your puppy a couple a few minutes to get used to the collar.
I prefer nylon or Nylon/chain collars in small puppies and then when the real training starts use a choke collar.