Just wondering if anyone knows the best way to do this. My submission is going to be for Maze Rats so I think it will  be pretty easy (and I can reach out to Questing Beast on reddit) but are we required to add things like creative commons license, attribution to the authors, etc?

I take no responsibility for your decisions regarding this, and won't be checking, but I would encourage you to do those things and otherwise follow the laws and customs of IP within reason, as you understand them. 

Do note that mechanics aren't copyrightable, and in many cases an OSR game is automatically taking adventure of a CC or OGL license that gives you full legal freedom to make derivative works. 

Also please note that no one makes enough money at this to actually get sued over it, so this is more about social norms than actual laws. 

Hey, y'all. This is how Copyright works. 

https://www.copyright.gov/help/faq/faq-general.html

Technically, it's copy-written the moment you create it, but you'll have to register it if you want to sue someone for infringement

Here's instructions on how to register your Copyright: https://www.copyright.gov/circs/circ01.pd

I included a blurb and link at the beginning of mine and also ran it by the author to make sure I didn't step on any toes.  Color me cautious/paranoid.  :-)