Easy way to use Google geocoding through Excel:
http://policeanalyst.com/using-the-google-geocoding-api-in-excel/
Working with XML Data in R
Step by step instructions on reading/parsing XML data using R-Project. from Informit.com written by Tobi Bosede
PDF: Working with XML Data in R _ Working with XML Data in R _ InformIT
Data for Radicals
Another blog by Lisa Williams, author of Life and Code, a blog that curates beginner resources on learning to program for journalists and other busy people.
World Bank Data
Link to data library from the World Bank.
MySQL to GeoJSON Using Python
Very useful link: How to take data from MySQL and output GeoJSON using Python.
City of Chicago Map Data
A large collection of mapping data published by the City of Chicago regarding the City of Chicago:
Tennessee Map Data
Link to mapping data on Tennessee provided by the state of Tennessee. Data includes roads and interstates, administrative boundaries, school district boundaries, and more.
California GIS Data
GIS datafilee published by CalTrans. Includes airports, highway network, truck network, AADT, rail data, and administrative regions.
Oregon GIS data
Link to state of Oregon GIS data.
San Antonio, TX GIS Data
http://www.sanantonio.gov/gis