Can someone eli5 sickbeard post processing for plex?

I have spent months googling for a decent post processing tutorial and none of the ones I have found are working for me.

Just to make things clear sickbeard and sabnzbd are both working fine and downloading shows automatically for me. Its just the automatic post processing I am having problems setting up.

edit: problem solved, on the search settings page of sickbeard I changed the nzb method from "black hole" to "sabnzbd" put in all of the appropriate details and this fixed my post processing issue.

I am on snow leopard if that info helps.