Schemers is a study group for those interested in exploring Structure and Interpretations of Computer Programming (SICP), an introductory Computer Science textbook used by MIT. The textbook is available in its entirety online for free: http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-10.html#%_sec_1.1

You should read the section and take a stab at the exercises before the meeting.