What I'm specifically asking is not tutorials or code academy-like websites.
I'm looking for primers/website/books that organize information about computer science and web development, for example: how does the web work? What is a session? What are protocols?
The information I'm looking for is the type you learn in a Computer Science class, not something like Udacity.
I want to know and why how stuff works, not just "this is how you do it."
The reason for this is because I’ve had some entry-level web dev interviews, but I didn’t know enough of the basic foundational questions to get past the 1st round. I attribute it to my lack of formal education in the computer science field. At best I can categorize myself as someone who just hacks code together (I think someone used the analogy on HN, the difference between a cook who cobbles food together and a chef who creates and innovates?).
EDIT: Thanks! I've got a lot of information from everyone and I'm going to go through it bit by bit.
I realize I wrote a rather misleading question. I am interested in Computer Science and its abstract topics as well as networking/web topics. I want to know what technology I'm working on and how it works, and I want that theoretical background so that I can be a better programmer.
For example, here's RFC 2616 (http://www.ietf.org/rfc/rfc2616.txt), the primary definition for HTTP/1.1. Try writing a web server just using sockets in Python/Ruby/whatever, based off of that. Don't worry about performance, handling more than one client at a time, or covering the complete spec, just look at how the essentials fit together.
I learned a LOT doing this (in Lua); I learn best building from the bottom up. If you learn better top down, try digging down from whatever platform(s)/framework(s) you're using now.
If you want to dig deeper, look into distributed systems, Unix network programming (Stevens's books are great), and let your interests lead you from there.