A good starting point for learning to repair computers is building computers. You learn how everything is put together and how to install the software. Of course, that really isn't practical for most people.
Experience. You can't really learn everything from watching tutorials and reading books. I'd say reading the Computer HW/SW part of CF everyday and seeing how people deal with problems would be your best option. That's how I learned most of my stuff. You won't really get much in depth of each part, but you'll know how to deal with like 90% of everyday problems people have. Once you know the basics, you have the knowledge to search for deeper answers.
I have a friend who's in the same position. Only he decided to read books about computers. Absolutely no help at all is what I can say came form those books by "experts." Sure he knows what a RISC processor is, but he has no idea where they are used or why they are good for that purpose.
Read forums, design computers, google everything. Building a computer (even only fictionally) and researching all the components can open up some interesting discussions between people on the internets.
All the knowledge won't come over night I can tell you that.
I started out reading and learned the basics but the book didn't show how to put a computer together. So I ordered a kit. Before it arrived, I went on the Internet and found instuctions on how to assemble a computer. Good thing I did because the computer had no instructrions!!!! Is this normal?
When the computer arrived, I took my time putting it together. When I ran into a problem, I went to the Internet and You Tube to see if I could solve the problem. When these options failed, I asked questions on this forum. I'm happy to say my computer is running well and I'm very happy with it.
The rest of my education will have to come from hands on and school. These are expensive routes to take but I guess the next step necessary. Is school worth the money? Wouldn't it be better spent on buying different parts and putting them together and getting that hands on education? Maybe I need to start advertizing on selling new computers first and then work into repair. Any thoughts on this guys?