Booker died a couple of months ago (a very hard couple of months because of other tragedies, as well, in the interim). However, last Saturday, we finally got a new puppy, Rocky. He's three months, and just out of the pound. A German Shepherd/Rhodesian Ridgeback/Golden Retriever and who-knows-what mix, he's quite cute. But he is probably the mouthiest dog I've ever had.
Despite this, I have traditionally done several things to combat mouthiness, and am doing it on him now. Nylabones, yes. But don't just keep them in your pocket. Throw nylabones, Kongs, toys, everything all over the floor, so he has the ability to chew on something proper. When he starts chewing on you (or relentlessly chewing on one of your older dogs who pleadingly looks to you for protection), say, "Aaa,aa!" and pull out the nylabone/kong/canvas cat or whatever else you have on you for him to chew and stick it in his mouth. Then say, "Good boy!" and praise him lavishly.
Get some bitter apple and surreptitiously apply it to your hands so that when he bites your hand, it is "booby trapped," and he soon learns that it does not taste very good.
Yelp and cry loudly whenever he bites you, so he knows he is hurting you, and learns not to do that.
Also, occasionally reprimand him by yelling, "no!" or "no bite!" when he does it.
Finally, occasionally, while he is still a puppy with needle teeth, if he gets your hand or fingers inside his mouth, push down on his tongue with one of your fingers just long enough to make it uncomfortable for him.
Consistency on all of these things seems to work after a couple of weeks.
On a brighter note, Rocky seems to be very intelligent. House broke him in a day with only three accidents. He has learned to sit, down, shake hands, exit through the doggie door on command and come in only three days. Doesn't seem to be much of a barker, but I recognized that he would be a massive chewer within five minutes of meeting him. So, I was prepared when I got him home, and I have probably spent close to $60 on chew toys already.
Here he is: