Most people know that there's screen to leave scripts running when you disconnect from your server. But in case it's yourself administering your server and not just some script running, tmux is a viable alternative.
Articles in the server-guide category
Do you want to know everything that's spoken in an irc channel, do you want to receive every query even if you're not in front of your computers? Do you dream of idling 24 hours per day, 7 days per week? With your server, ZNC and your regular irc client, you can do exactly that. ;)
What's the most important service on a linux box, the one you never should risk breaking? Right, it's ssh. Therefore the first entry in the server guide is on configuring ssh and your working environment for what will come next.