Packt has an eBook sale going on. All eBooks are $5 including lost of the spatial books including the new PostGIS Cookbook that comes out next month.  Other spatial books of note include:

• Programming ArcGIS 10.1 with Python Cookbook
• Learning Geospatial Analysis with Python
• Google Maps JavaScript API Cookbook
• Learning QGIS 2.0
• Python Geospatial Development – Second Edition
• GeoServer Beginner’s Guide
• OpenStreetMap

The sale ends January 3rd so you have some time.