List of links to useful geographic and conventional data sources.
gadm.org - downloadable spatial database of the location of the world's administrative areas (or adminstrative boundaries)
IBGE - Geociências - Cartas imagens, imagens aéreas e orbitais, mapas, malhas, atlas, entre outros.
IBGE - Estatísticas - Censo e outros dados.
Plano Nacional de Logística de Transportes
Geofabrik - Data extractions of OSM by regions (from continents to city level).
Planet OSM - Complete dump of OSM database.