Here are a few free online tutorials for learning how to work with and create maps using US Census data.
Ardit Sulce has compiled a series of four videos showing how to download, analyze, and map US Census data using QGIS. The series takes users through how to download any data from the census website, join CSV files with shapefiles, normalize the data, make thematic maps, add map element such as legend, title and scalebar and finally export your map to a PDF file. Visit: GIS Census Tutorial -Donwloading, Analyzing, and Mapping Census Data
Ari Lamstein has a free email course that guides users through mapping US Census data using R, an open source software environment for statistical computing and graphics. The email course contains five lessons with three days in between each lesson. More: Free Email Course: Learn to Map Census Data in R
For those interested in working with ArcGIS, the Spatial Humanities offers a step-by-step tutorials showing how to join Census data with shapefiles using ArcGIS.