The TCS Committee is a standing committee of the Washington Apple Pi Board of Directors. Its charge is to build and maintain the electronic communications infrastructure to facilitate the Pi's online community.
The committee (the crew) used to meet every Saturday at the office, back when the sights were lower and the work more fun. Now it's pretty much by appointment only.
The crew's only mailing lists are for mechanization and infrastructure, and are of little use to the public.
The TCS FAQ is a pretty good read, explaining much of the purpose and history of the committee.
The TCS itself is of course the main focus of the team.