California Soil Resource Lab Tutorials - The UCDavis Soil Resource Laboratory reference site provides useful tutorials on using open source GIS tools such as GRASS, PostGIS, GDAL, OGR, KaMap, R statistical package, QGIS and UMN Mapserver and applying these tools for use in scientific research.
GeoMusings - Bill Dollins - GeoMusings - focuses on using ArcGIS suite of tools in conjunction with open source tools.
Maptitude Training - Tutorial teaches how to get started with Maptitude. Each lesson describes an important software feature and concludes with a review exercise. Topics covered include: maps, themes and legends, dataviews, selection sets, figures and layouts.
MassGIS Geospatial Web Services Wiki - Primarily focuses on how to use MassGIS web services, but also useful as a general purpose resource for querying OGC compliant WMS and WFS services. Examples querying geoserver.
