I’ve been toying with the idea of having a little hobby computer store for years and I’ve reached the point where I feel I have nothing to lose in trying it.

I don’t intend to make it my main source of income but I’d like to have some sort of formal knowledge base to resort to, regardless I’ve been acting as the tech guy for several years for a lot of people.

Where can I find some good courses/resources, preferably online, to improve my knowledge base?

I’m a long time Linux user so I intend to use my hobby to make some noise about it.