I think this is what is needed the most, a basic FAQ explaining why and how.
But in short, it does act like Reddit. By default, you will see Hot topics on the main page, aka recent topics that are the most upvoted. The other sorting options are Best, the same but without the time factor, and Recent, which is Hot but without the upvote factor (aka most recent).
As for the topic, they're roughly the same. They basically based on a debate. So you have a topic (the thread), and replies. You can then choose to reply to the topic, or to a specific reply (aka indented replying). Then you have listeners (other users) that can come by and upvote/downvote threads and replies based on how relevant and useful they are. This amkes it so at first glance, you will always get a good idea of the most relevant and useful information.
As for formatting, it isn't quite there yet, for npw try to use the Formatting Guide, or read up on Markdown. If yo uhave more question, jsut ask away, users and/or designers will probably be happy to answer.