I don't know myself, but here are some possible answers:

https://mathoverflow.net/questions/114034/learning-path-for-...

Edit: Here is another overview that seems good:

https://www.math.ucdavis.edu/~osserman/math/pcm.pdf

Yeah, it's still incredibly difficult terrain, despite all the time that's passed. Wrestling with Hartsthorne is still a rite of passage for students in this area. I am (very) intrigued to know what would happen if someone made a serious effort to make the ideas more accessible. It remains an area where the depth of knowledge required is legitimately deep: would be cool to figure out which ideas are actually independent of other parts of the stack.

Take a look at the stacks project: https://stacks.math.columbia.edu

A cross between a wiki and a collaborative textbook.