Please read and take notes on Chapter 1 of A Survey of Buddhism by Sangharakshita. You will need to bring the text with you. At present, this text is in print as part of Volume 1 of Sangharakshita's Complete Works. If you have problems getting hold of the text please let us know as soon as possible.
You can also listen to the Chapter.
Background reading:
Sangharakshita: What Is The Dharma?
Subhuti: Revering and Relying on the Dharma
You may also want to watch or listen to Vajratara's overview of the first Chapter of 'The Survey'.
Transcendental Principle 2 retreat:
Subhuti's paper Revering and Relying upon the Dharma.