U.S. Broadband Availability: June 2010-June 2012: A Broadband Brief
http://www.ntia.doc.gov/files/ntia/publications/usbb_avail_report_05102013.pdf
Covers current availability speeds, changes in availability during the two year period, and disparities between rural and urban access. Also identifies states with best access and percentage of counties with access to various speeds. From the National Telecommunications and Information Administration