WikiProject Guinea
From OpenStreetMap Wiki
Guinea - Guinée
Download OSM data extract for Guinea from Cloudmade.
Conakry
There is Yahoo! hi-resolution images available for Conakry. So one can sketch over roads and features with potlatch or JOSM.
More satellite images
The coastline around Conakry is mostly wrong. See this ESA picture for reference. There are Mangroves north and south to the city.
Nasa's Earth Observaroy has images from 1986 and 2000.