This guide includes how to getting data from Census and other sources for use of GIS.
Geocoding: a process to convert addresses into coordinates ( latitude (X) and longitude (Y))
Georeferencing: a process to convert print or scanned image maps to georeferenced maps to use in GIS analysis.
Map Projections: representing a 3-dimensional earth data into a 2-dimensional data based on various models.
Other Tutorials in GIS (via Lynda.com): A list of essential GIS tutorials (video)