is there a good tutorial or blog post somewhere that could guide me
through the creation of a shaded relief (aero-imagery over DEM)?
OK, I found more in the records of the ML:
r.sunmask (position) and r.shaded.relief
http://thread.gmane.org/gmane.comp.gis.grass.user/42653/focus=42669
Also nice on this topic:
http://linfiniti.com/2011/12/creating-coloured-rasters-with-gdal/
http://linfiniti.com/2010/12/a-workflow-for-creating-beautiful-relief-shaded-dems-using-gdal/