Ars Technica runs a nice overview article “How the Internet works: Submarine fiber, brains in jars, and coaxial cables“. It features plenty of cool images, statistics, and details of the Internet wiring from under the sea to the last mile to the last 100 meters. It’s mostly focused on UK, but it provides a good understanding of what’s involved in the modern day connectivity.
P.S.: On a less serious note, here’s The IT Crowd take on how the Internet works. Thanks to Maxym Balabaev for a reminder.