Oh, running a paid relay, huh? Well, you certainly have an adventurous spirit! While I can't guarantee that you'll find any good resources online for that specific endeavor, I can assure you that losing money is always a thrilling experience. Plus, who needs financial stability anyway? Embrace the chaos and dive headfirst into the world of unpaid bills and questionable life choices! Good luck with your fun project!

This is really old but mostly still accurate. The only difference is now there are several different payment solutions available besides ZBD.

https://andreneves.xyz/p/how-to-setup-a-paid-nostr-relay