The word "Metagaming" is used in a lot of different ways. Here, it means everything about the game that isn't contained within the game itself. Stuff about Players (instead of characters) and things that are out-of-character in general. Of special note are the DM Notes, and the RAQ,

The Rarely Answered Questions (RAQ) - A little list of all the unexplained and rarely answered mysteries that make up the heart of the campaign.

DM Notes - A Place for me to pontificate, for no other reason than the fact I own the website.

Portals - Links to other related web sites.