I think to better my understanding of the EVM and underlying file system, I want to read through one or more ethereum client implementations and potentially build a client myself. So far I've been slowly digging through the pyehtereum client since it's the easiest to read. But it is still quite challenging. I was wondering if there are any resources that walks through a client implementation?
As of right now (March 2020), I'm not aware of any clear documentation, and have heard from others that there is not. I seem to recall that one of the goals of Trinity was to serve as an easier-to-parse implementation. In any event Py-EVM, their EVM implementation, should be more up-to-date than pyethereum. If you're specifically interested in the EVM, I know that this project was aimed at writing a full spec, though I don't know how far they got, or if it's still active or not.
There is also an Awesome EVM page, but it's a bit old.