There are two websites that will be useful to you in compiling your Statistical Profile for your group project.  The first is Social Explorer: http://www.socialexplorer.com

Social Explorer allows you to access U.S. Census data going back to 1790.  You can access data for particular zip codes or census tracts (generally a smaller geographical area) and use Social Explorer to map this data.

The second site is Infoshare: http://www.infoshare.org/main/directip.aspx

Infoshare compiles multiple data sources for New York City.  It has more comprehensive data than Social Explorer and can sort data by neighborhood, Community Board or borough.  It does not, however, produce fancy maps.