Go to the Library's Research Guide on Finding Data: Demographics, Source by Topic, Demographics for links to useful resources including a link to the following suggested resource. 

American FactFinder which is produced by the US Census.  

Go to the Library's guide on Advertising Research and Planning, Marketing, Demographics and Ad Spending tab which provides targeted resource and research suggestions.

Go to the NYU Business Library's Company & Financial Information section for links to useful resources including a link to the following suggested resource:

Mergent Intellect: Choose Demographics which provides latest census data by zip code, MSA or Industry.