Since I entered the nix world, its documentation has been very chaotic, but with months of in I’ve fallen in love with Nix and have gained a quite clear vision of Nix & NixOS. Hence I’ve made my notes for personal and public use:

https://animeshz.github.io/site/notes/20-29--DevEnvironment/21--Linux/21.02-Nix.html

Hope it’d be useful :)