Using Quantum GIS to join your data. Once in QGIS, first load the shapefile by clicking the Add Vector Layer button. Click Browse then find your shapefile and Open it. You should now see the geometry displayed in the map window and the filename in the Layers panel. Repeat steps 1 and 2 for your .dbf file.
Making static maps and processing geodata with QGIS Introducing QGIS. GQIS is the leading free, open source Geographic Information Systems (GIS) application. It is capable of sophisticated geodata processing and analysis, and also can be used to design publication-quality data-driven maps.