J.F.
Go to the library and ask for help in finding books on child development.
There are some that are specific to boys.
Michael Gurian has some excellent books on boys---The Wonder of Boys" and "The Good Son" are two that are good sources.
You can google these titles or look them up on Amazon, and they'll suggest other books on the same topic.
Also, if you're taking your son for his regular well-checks, your pediatrician should be able to address your questions. Usually, there is a hand-out given at each check that notes milestones, expectations, and safety reminders relative to the child's age.
Start there and post again if you have more specific questions.