Restricting nosey userson a home network

Question

I have nosey people in the house, I am A 36 yr. old man and i frequent p**n sites on my own comp.There is another desktop in the house and we share a dsl connection via a belkin wired gateway router, i'm not very knowledgable when it comes to alot of this computer stuff. So if you could help me keep others out of my comp. i would appreciate it.