[neilv]

This is a pretty low-level mechanical thing, but your first day/week is the best time to do it...

Almost every time I join a company/project, they don't have even remotely accurate docs about how to set up a development environment (configure workstation with prerequisites, check out the code, run the code).

If they already have a wiki page you can start editing, great. If they have a wiki without such a page, great. If they're open to having this info in the README.md of the repo, great.

Document everything you have to do, which the next hire probably will have to. (Example: Don't have some credential or authorization to access the repo? Ask around for how to get it, someone tells you that you go ask person X? Document who someone should ask if they don't have that thing.)

If you're not sure whether you'll be stepping on toes, make the notes in a file in your home dir, as you're going through it, and later ask someone about whether it'd be helpful to new hires to put it in the wiki/repo/etc.