If you are looking for GIS reference materials, I have found a few excellent and mostly free online books and journals that are valuable for both the novice and seasoned GIS user.
Geospatial Analysis: a Comprehensive Guide to Principles, Techniques and Software Tools by De Smith, M. J., Goodchild, M. F., & Longley, P.
This collection of work by an international team of academic authors is intended to provide explanations about spatial concepts and techniques independent of any particular GIS software package. Examples of spatial analysis are provided using a variety of common GIS tools such as ArcGIS, Idrisi, Grass, and Surfer. The book originated as a set of materials to accompany the spatial analysis module for the MSc program at UCL and evolved into a larger and more detailed spatial analysis series made freely available via the web by the authors. Longley is a professor in the geography department at University College London (UCL), de Smith is researcher and lecturer associated with UCL, and Goodchild is a professor in the geography department at the University of California, Santa Barbara (UCSB).
Cartography and Geographic Information Science – Editor: Leitner, M.
This journal contains peer-reviewed articles and book reviews covering a range of topics relating to GIS. For example, topics in a recent issue include articles about using web lectures to enhance GIS learning, digital elevation models, and a book reviews about the use of GIS in archaeology. This peer-reviewed journal is published by the Cartography and Geographic Information Society (CaGIS). The journals also became one of the three journals of the International Cartographic Association in 2004.
Beyond Mapping Compilation Series by Barry, J.K.
Three hundred articles written over twenty-five years were republished as part of this online book series. The depth of the work written over a quarter of a century provides a look at the evolution of GIS as an analytical and data collecting tool. Prior to publishing this series of work, Berry was a longtime contributor to Geo World magazine and the principal of a GIS consulting firm. The author of nine books about GIS, Berry is currently the Keck Scholar in Geosciences at the University of Denver and an Adjunct Faculty member in Natural Resources at Colorado State University. The series is available both online and as a set of four printed books. The online web site is divided into four categories covering GIS modeling, map analysis, spatial reasoning, and concept, issues, and algorithms in GIS.
- Free GIS Books
- GIS Books
- Publications Category – News about GIS books, magazines, and online geospatial resources.