Census Tract Maps with Demographics
Census tracts by themselves are only useful if you already have a clear idea of the profile of your territory. If you have a list of tracts you already know you need to increase penetration within, then a simple tract map will suffice. However, if you are trying to present a visual case for why some areas are underserved or why other areas should be targeted, shading tract maps with income (or other demographic) can be a real eye-opener. You can order a custom map with demographic and census tracts online.
Particularly with CRA or HMDA compliance mapping, demographics provide a regulatory role as well. There are specific income criteria that must be observed.
Free lookup by county: http://www.ffiec.gov/census/default.aspx