Socialization is the process by which individuals acquire the knowledge and skills necessary to conform to the norms required for integration into a group or community.
There is no standard way to socialize your puppy.
You must start socializing your puppy from day one, as soon as you get it. The opportunity for socialization is at its peak between 8 and 16 weeks of age and remains until the puppy is about six months of age. You must not waste this period. If you do, you will not be able to re-gain what you lost, only attempt to repair it.
It is not enough for your puppy to feel comfortable at home and in your favorite dog park where it goes for a walk every day, plays with the same playmates and greets the same people. You need to expose the puppy to (many) strangers, people as well as dogs, and to new environments.
Exposure to novel stimuli should happen gradually.
Allow your puppy to play with other puppies as well as (sociable) adult dogs. Growling, snarling, barking are all normal canine expressions and there's nothing wrong with it. Rough play with other puppies teaches your puppy the boundaries of social interactions. Your puppy learns self-control by playing with others. It learns good manners and when enough is enough.
Your puppy should go out every day and have pleasant experiences with all different types of friendly people (adults and children) and friendly dogs (of many different sizes, shapes and ages).
From Dr. Ian Dunbar's Ten Important Skills to Teach Your Puppy