A Website for everything

Hi everyone, here we are again. Today’s topic is about a website or an expert related to our career, and I really don’t have an expert related to my field to talk about,  so a website is my only topic, and I think, for me, there isn't a more versatile and helpful website than Youtube, honestly I use it mostly for entertaining, but when the time comes, I can find really interesting videos about how a monopoly works, the fertilization for fruit trees, the effect of a freeze on the crops, the fluid mechanics, the anatomy of fungus, even the explanation of concepts related to the edaphology, all of these, are topics related to the subjects of my career, that you have to study and learn in some moment of it. So, as you can see, Youtube is a really powerful tool for the study, better in some ways than other websites, because as may you know, a video is worth more than 1000 words. Now I would like to know what are some you favorite websites related to your career, or maybe  unlike me , you have some expert that you really  admire.