There are many books on the topic of spatial analysis; some of them are very comprehensive and address various issues – spatial statistics, network analysis, cell-based raster analysis, to mention just a few. Among those books, I should emphasize the importance of the book I have been reading lately – Geospatial Analysis – a comprehensive guide, by de Smith, Goodchild, and Longley. Many people doing research by using geographical tools might find this geospatial analysis book extremely useful. Even if you work with the specific type of analysis by using a certain open source or a popular commercial GIS product (for example, using ESRI Geostatistical Analyst® for coverage analysis), you could get a deeper understanding of raster data properties and learn some more theory behind the interpolation methods you use.
The book is available in a Web version as a compiled book in the HTML format (for free) as well as a printable .pdf file (for purchase). This book is very well structured and it is very easy to navigate among different chapters. Personally, I have found much of value in the network analysis section: one can find algorithms description, location and service area problems analysis, and location network analysis concerns. I would advise you to spend some time on reading the book, which is the most comprehensive guide on geospatial analysis I have ever seen.
Another just published book on spatial statistics includes a very interesting chapter about using ESRI tools from ArcGIS Spatial Statistics toolbox. This book will be useful for anyone who interested in working with spatial statistics and learning more about the ArcGIS geoprocessing tools. This chapter is available for free at the Springer web site.