I have a personal database of cartographic maps that I used for many purposes, mostly planning campings and other outside adventures.
I'd like to have similar data about Brazil.
Open Street Maps and GEOTIFF Files from MODIS, wold do the job.
As other have already mentioned, Open Street Maps is your friend. The covered details depends largely on the number people that have visited the region and actually added data to OSM. You can get an idea of how much detail in a region is covered at the Garmin osm site. The size of each tile more or less reflects the size of the resulting image file. The more details, smaller the tile. This is a very rough estimate though. It does not mean that the bigger the tile the lesser the quality. Some brazilian regions (e.g. The amazon), do not contain that much infrastructure to cover.