I'm a Firefox noob too, ehBeth! (I'm still trying to figure out how to use Twitter.
Tried to send a private tweet to Robert today and couldn't find an obvious way to do it with the onscreen menus. Didn't have time to go searching for beginner tutorials.)
Here's a link to the BBCode thingy:
When it is installed, you can add customized tags to it. To use it, you just right-click in an editing field such as a post form and it gives you selections to choose from. I'm still adjusting some of it to mimic the exact codes we use here.