Lol, open question much?
No single source, initially reading Weis TATH, Williams MTM, and feedback and learnings, past and present, specifically from Jako, Mitta (both to whom I feel incredibly grateful for their sharing of their learnings) and a few others, gave me a taste of Wyckoff and VSA that led me to seek out further info, deepen my current understanding and answer questions I had, without asking a gazillion questions in here.
I do tend to stay up till all hours reading various online sources, watching clips etc., following others more skilled than I around the world sharing their work elsewhere and asking questions where I have the opportunity, downloading reading material, rereading things that somehow now read completely differently than last time I read them and of course playing with my charts as well.
I find it all fascinating which I think, for me, helps, as it provides the energy required to continue researching and fulfilling that unlimited desire for answers and knowledge, when I'm not completely knackered from home, kids, work, CFA, gym, etc.
Whenever a question arises I do my best to get to the bottom of it but often seeking the answers just opens up a whole new set of questions, sometimes it just feels like I'm going around in circles and getting nowhere but I believe it's like assembling a giant jigsaw, if I just keep working on smaller sections, slowly but surely the pieces come together, and some things that at the time didn't really make much sense suddenly fit in and the picture becomes clearer.
I'd love to able to say here that I've personally studied and completed various courses under Wyckoff masters, wish I were that lucky, maybe one day, possibly not too far away if I am that lucky, but for now I'm just limiting the type of information I digest, as best as possible, specifically to Wyckoff and related topics, I found this step alone has helped me immensely, at least to obtain some focus, as I truly believe this is the best foundation for me to develop my future trading/investing skills.
I am still learning and I know I will make mistakes but hopefully they can just become learning blocks of a bigger picture that I've yet to develop.
Hope that helps you to understand where I'm coming from, why do you ask?
Cheers HF