Does anyone have any other guides like this? I'm using Arch Linux and want to run nginx on it. I'd like to make sure it's as secure as I can make it before deploying the website.
The NSA's STIGs are a useful resource. If you want the higher-level policies they come from, NIST[0] is one candidate.
If you want documents around the same level of specificity as the STIGs, you'll probably need a non-governmental source. Arch Linux and Nginx are not EAL certified[1] at any level, so the US Government isn't even going to try to secure them.