Here is as much information as possible about Tae Kwon-Do. Its pretty vast so don't expect to learn it all in your first visit! You should build up your knowlege of Tae Kwon-Do to match your grade level, and the theory questions that are likley to be asked of you at that grade level. So if your a white belt don't worry about learning the Korean for flying side kick until you use it, like in pattern Choong-Moo at Black Stripe level.
The encylopedia has been split into its relevant sections, click on the link to move to that section
Here you will find an un-biased history of Tae Kwon-Do
Here is a full history behind the meanings of the patterns
Here you will find pictures and descriptions of the Tae Kwon-Do Stances
Here you will find the definative English to Korean Dictionary