Hi Riley,
sorry to hear about the problems with your Newfie puppy, there will be lots of good old posts on this topic for you to read through, quite a lot of people have experienced the same sort of problems with their pups when they were very young. (Me included).
Training school as soon as possible is a good start, puppy pre-school maybe, as he is probably too young for 'real' training classes yet. (They usually about 12 weeks before they can start them, I think). So you're definitely one step ahead of the game by calling a training person!
You will need to practive some dominance tactics by the sound of things. You could try the alpha-roll but I would read the post below titled alpha-roll before giving it a go, it is not for everyone. Other things I would try (and DID try, with my girl) is :
- thrusting your hand down your pups throat when they bite your hands, making them gag a little - it's kind of like a counter-attack and they really don't like it - I found this to be really effective.
- holding your pups mouth closed when they mouth you
- isolation for bad behaviour - for such a young puppy I would only do it for 10 minutes, maximum - I probably wouldn't use the crate for this though as you want positive feelings associated with the crate and not negative ones - maybe use the laundry or another small room.
- do alpha-type of things like walking through doors first, not letting them on furniture (it can make them think they're people!). I now let my grl on one particular armchair and on my bed, when invited, but could only really start doing this when she got older and her behaviour improved because it was causing a problem.
I know it seems really, really awful and serious now - I thought I'd made a HUGE mistake with Rory and had doubts and thought she was just awful at times - but it will get better if you perservere, it sounds like you are doing all the right things. Training school is what really corrected the problem for us. She used to growl, scratch, snap and bite from 12 weeks to about 5 months. It pretty much stopped when we began training, because she started to realise that yes, we WERE the boss of her! And not the other way around.
I'm sure others here can offer good advice or you could read back through the archives and you will find a lot of helpful stuff. (Set it to show posts from last year or so).
Good luck and keep us updated.