I was recently in the same boat.
A few helpful resources
(1) Patricia McConnell has a book called The Puppy Primer. I knew most of it already, but it was a very helpful refresher. If he is already eight months though, you may be past this.
http://www.amazon.com/The-Puppy-Pri...8&qid=1352034946&sr=8-1&keywords=Puppy+Primer
(2) DogStarDaily web site.
Many free articles if you search. Also, two free books, Before you get your Puppy, and After You get your Puppy by Dr Ian Dunbar. Again, you may be past these books,but they are free, so you can look and see.
http://www.dogstardaily.com/free-downloads
(3) No pull harnesses.
The one that a trainer recommended to me was the sense-ation
http://www.softouchconcepts.com/
There are others though that you can get in the pet store. Just be careful, not all harnesses are no-pull. I believe the no-pull ones usually attach in the front, but I could be wrong.
(4) Red light/ Green light
If the dog pulls, you stop. If the leash is loose, you walk.
(5) Turid Rugass has a couple of books
My Dog Pulls, what do I do
http://www.amazon.com/MY-DOG-PULLS-...8&qid=1352034613&sr=1-4&keywords=Turid+Rugaas
Barking the sound of a Language
http://www.amazon.com/Barking-Langu...8&qid=1352035346&sr=1-3&keywords=Turid+Rugaas
As far as the pup nipping at you, I believe you want to yip like he really hurt you. Do not scold him, just act like he hurt you.
For the barking, I believe the key thing is to not reward the barking, reward quiet. So he never gets a treat if he is barking, he never gets petted for barking, you can even look away if he is barking. Try to reward quiet. Barking at people going by is tough. Is this inside or outside? If inside, can you pull the shades so he can't see them. When he can see, maybe you could get him to focus on you and reward him for that?
As far as being skiddish with people, will he take treats from other people? I try to always have treats on me to give to others to give my dog. If people are coming over, I meet them at the door with treats to give the dog.
Hope some of this helps. Good luck and enjoy the puppy.