These are my NixOS configs. There isn't much here that is useful for anyone else. Feel free to look around and borrow snippets as you see fit. I wouldn't bother trying to use them as is to configure your own systems, unless you have a laptop identical to mine and really want the username "stusmall".
The bootstrap.sh script is used to create links as needed. It will link from /etc/nixos/configuration.nix to the relevant entry point. Each system I have has its own entry point (desktop.nix, dell.nix, etc) which will then import base.nix and then any other modules it needs.