Here is a book to help you use your GPS unit. This topic popped out at me: your cellphone uses ‘Assisted GPS’ which combines GPS signals with cellphone tower triangulation (if you have paid fees…). You will find other interesting topics here. 350 pages.

“Mapping Global Cities: GIS Methods in Urban Analysis shows how the analysis of relevant data with GIS can provide a powerful new perspective in addressing urban research and policy questions, and it enhances our understanding and efforts in solving urban planning problems. Author Ayse Pamuk draws upon her extensive fieldwork experience in developing countries, over ten years of work as a university professor, and extends it in new ways by using the power of spatial analysis with GIS.” — from the ESRI site.

Here is a book for users of GIS systems. 350 very readable pages.

It used to be that a GIS package cost thousands, and you had to attend university to learn how to use it. Now there is Google Earth and related sites that are free unless you want a pro version. Here is the user manual!