tinker around with your pc.. just make sure the power's turned off lol...
If you're a practical person like me, fiddling and learning what each parts do (by way of google, wikipedia, asking people, or trying it yourself) is the best way to learn how to troubleshoot.
Places to find solutions, usually reside in google, microsoft's knowledge base, some threads here and other forums.
It really depends on what field you want to learn? security, networking, hardware, software, OS, code, internet etc...