A career-related website / an expert on your field

A career-related website / an expert on your field

 I think one of the website i more visit is youtube because there i find a lot of people who explain things about maths and music, many of them are professionals who have found on youtube a place for make money or simply to share their knowledge, but obviously this site isn't official for a thesis or something like that.

 I like to read books too, when i'm searching for some information especially when is about calculus or physic. I don't have any of this books but i look them on internet, most of the time i find them for free or i can borrow a book on the library of the university or any library of the city.

 So i don't really see websites or blogs to find information that's why i can't mention any, maybe in the future i'll find a good website to read something about a topic more specifically of my carrer.