One thing to remember is that puppies will teeth just like babies will. When puppies are teaching they do a lot of chewing to treat the pain. They will chew on anything they can get their mouth around. This includes things like shoes, table legs, kid's toys, chords, sticks, bones, and your fingers!
You can give your puppy a special treat when they're teething. I got a washcloth wet, put it in a Ziploc bag and then froze it. Once it was frozen, I took it out and made it to the puppy to chew on. The cold washcloth helped to numb the pain. The only problem with this is the washcloth did not stay frozen very long.
I had read somewhere that you can do the same thing with a dog toy. I took one of the dog toy routes and froze it in a Ziploc bag. The problem I had with this is that the dog rope toy was too large for the puppy to chew on. If you want to have the puppy chew on a frozen dog toy, make sure the toy is small enough for them to hang onto and to chew on.
One thing you do not want to do is to give your puppy a regular baby teeth ring. The teeth rings for babies are usually filled with liquid that you can freeze. A baby's teeth are not as sharp as a puppy's teeth. The puppy will chew holes in the teeth ring in a matter of minutes. You will then have a wet mess on your hands, and I do not know how safe the liquid is inside the teeth ring.
When your puppy is teething try to keep some cold toys around, and also a variety of toys for them to chew on. This will help to keep them entertained and away from things you do not want them to chew on.