Does anyone have any insight on the directory structure of Linux or could point me to a source?
There is no fixed standard, each distribution has it's own (and no the kernel doesn't have any directory structure either). However, related distributions have very similar structure, say all the debian based distros. some common features are pretty standard, such as /usr /lib /var /etc /home. How files are distributed in these dirs is completely another topic and distros do differ.
There have been some
attempts to standardize the structure, but they haven't been very successful. LSB is probably the best attempt so far, but it isn't perfect either.