They don't understand time outs so forget that completely - it does not work.
Correct the pup when growls and nips. This is important to ensure that the pup understands that this is not acceptable. Correction however does not mean hitting or putting in a crate.
Hopefully LuckyPenny will sign on and assist you as she has extensive experience with puppies. I cannot as I am only adult oriented and my method will not be the same for puppies.
More advice I am certain will come from other members more puppy savvy. In the meantime - good luck and I will continue to read this thread to get pointers myself.