It sounds like you are a homeowners association.
Ordinarily you file a form 1120 or 1120 H, See instructions for 1120h and definitions:
http://www.irs.gov/pub/irs-prior/i1120h—2008.pdf
The one wrinkle in my situation is that I'm dealing with a commercial condominium, and it looks as is that form is specifically for residential associations.