Geospatial Historian Blog "A tutorial-based open access textbook ... designed to teach humanists practical digital mapping and GIS skills that are immediately useful to real research needs." Include instructions for georeferencing and vectorizing scanned maps using QGIS.
A Geographic Information Systems (GIS) Training Manual for Historians and Historical Social Scientists Provides an introduction to GIS for these disciplines, mostly using examples with the open-source software MapWindow GIS, along with some ArcGIS tutorials. Includes free manual as well as tutorial data. Chapters are: 1. Geographically-Integrated History; 2. Getting Started with MapWindow GIS; 3. Datum and Map Projection; 4. Cartography; 5. Symbology and Data Management; 6. Basic Spatial Analysis; 7. Data Normalization; 8. From a Paper Historical Map to a Digital One; 9. Digitizing; 10. Raster Data; 11. ArcGIS Tutorials
Spatial Humanities Step by Step From the University of Virginia. Includes postings on such topics as georeferencing historic maps or vectorizing their features.
WorldMap Warp Tool for georeferencing scanned historical maps. Visitors can browse maps others have geo-rectified or upload their own to rectify.