The most relevant journals are the International Journal of Geographic Information Systems (IJGIS) and Cartography and Geographic Information Systems (CGIS). Other journals include American Cartographer, CVGIP: Graphical Models and Image Processing, Cartographica, Geographical Analysis, Journal of Remote Sensing. Duane Marble maintains a ftp-able bibliography on GIS (in refer and mac, but not in bibtex format) on bastet.sbs.ohio-state.edu
Of course, the Web is a good source of information and data. The NCGIA activities occur at the University of California, Santa Barbara, http://www.ncgia.ucsb.edu/, in Buffalo, NY http://www.geog.buffalo.edu/, and in Maine http://ncgia.umesve.maine.edu/. Maine has some technical reports on line, including a 1992 update of the research agenda, 92-7.ps. BC environment has the NCGIA Core Curriculum on its Web http://www.env.gov.bc.ca/gis.
Xerox Parc has a map program http://pubweb.parc.xerox.com/map. NAISMap is a GIS on the Web http://www-nais.ccm.emr.ca/naismap/naismap.html. GRASS (Geographic Resources Analysis Support System) is a public domain GIS developed by the US Army Corps of Engineers http://www.cecer.army.mil/grass/GRASS.main.html. GRASSlinks is a Web interface http://www.regis.berkeley.edu/grasslinks/index.html. ORES has an extensive list of data sites and other information. See for example,
http://www.csn.net/~bthoen/ores/gis/index.html For GIS FAQ, see
http://www.census.gov/geo/www/faq-index.html Finally, for ESRI (ARC/Info), see: http://www.esri.com/.