I'm aspiring to be an expert at computers, and I was wondering where i should start?

I'm 16 years old, and I have decided I want to become an expert on computers. I know that in order to do this, I will need to learn how to program, how a computer works, and how to build a computer. Can someone tell me somewhere i can get started on this learning this stuff like a book i can borrow from the library or a website that can guide me in this path. My computer experience is amateur at best. All my friends that know a lot about computers laugh at my tech skills and they won't help me, so can anyone on yahoo answers please help me learn about computers. (Also, can anyone estimate how long it will take to hone these computer skills?)