I have been trying to find this webpage for a few weeks with no success, maybe someone knows what I am referring to and can point me out to it, I would really appreciate it.

I remember that a few years ago (it could be about 5 years ago or more) I found this brilliant resource about Machine Learning and Bayesian statistics. 

They had a big graph with all the important concepts in Machine Learning: You could click in every node (a concept, e.g. Maximum Likelihood) and see what things you need to understand first (e.g. basic probability) and to what things that specific point was a prerequisite itself (e.g. Expectation-Maximization). There weren't extensive explanations inside of every concept, but a long list of recommended resources, such as courses, videos or papers. There was also an option where you could just mark some of the nodes as "mastered" and then you could clearly see where you could go with the things that you knew, and what were the missing things you needed to master first to go study more complex stuff.

Creating a similar graph with the important concepts in LW would be great by the way.