some youtube links are outdated: try a search for a fresh link...
thanks very much, Moritz for your helpful info. I'm just trying to make sense of it now!
There was a blog written by one of the early members (The Phrygian Kid) that gives a great intro to music theory.
This is the link
I have heard that Alfred's essentials of music theory is really good for beginners
I also forgot to mention the book on which I learn this topic, namely The ultimate guide to music theory. This book helped me understand the basics, although I think it is suitable for both a beginner and a continuing musician. I also try to listen to various podcasts on this topic, so that while I'm doing my own thing, I can also study the music theory. Although most of the time I want to relax, and that's why I put something from the newest albums on my background and just enjoy what the musicians are doing now. I hope my comments will be useful for you, I would also like to be advised by these books at the very beginning of my journey