The first two volumes of NodeBook are complete and free to read online. Volume 1, The Node.js Runtime, goes deep on the architecture, event loop, buffers, and streams that everything else sits on. Volume 2, Networking & Protocols, covers TCP, HTTP, sockets, DNS, and TLS down to the internals, not just the API surface. Every chapter pairs with runnable Node Runtime Labs, plus EPUB, PDFs, slides, and cheatsheets. Two volumes down, five on the way.