It is hard sometimes to find verified statistical data. US Census Home Page may help. To search data in particular area you would need to go to American Fact Finder. US Census currently is working on simplifying the search technique and developing a new web page. There are some basic steps that you would do searching both sites - a New American FactFinder and the Legacy American FactFinder The latter will go away in Fall 2011.
New site has a nice Help page that will guide you through the Quick Start search or Search using categories and topics. Data search could be performed by using geography (maps), industry codes or population groups topics. After getting results arranged in the table, you also can create a reference map or thematic map based on this data.
By clicking on American Fact Finder Virtual Tour link in the content (left frame) you will be able to view a short video that will explain to you how to navigate this site.