Good thinking and welcome to the board!
When people talk about socialization they think of the first half of it - doing things with the puppy - but not the second, watching their reactions and modifying the exposure as needed. Depending on where a puppy is coming from - both internally in their genetics, and externally in their environment, they may need more or less help with modifications.
Some general links I like that will help to explain further:
Does Your Dog REALLY Want to be Petted? | eileenanddogs
Her links at the bottom are also great so check those out and these:
Learn about dog body language
Dr. Yin, in addition to the really great infographics that you can download for free that are linked in the first article, has a book/dvd depending on preferences on puppy raising: Animal Behavior Books and Products | Dr. Sophia Yin, DVM, MS
Calming signals, photos - Turid Rugaas - International Dog Trainer
really a great resource on dogs
Understanding that a puppy will bark at a tree, a person, a rock and that does not mean they are being protective is important - watching their posture, tail up, tail down, ears up, ears back, moving forward, moving backwards indicates curiosity or fear but as a puppy, not protectiveness. There are no attack babies in the human world either.
Enjoy your puppy!