Jonathan Williamson of CGCookie in this Blender 2.5 video tutorial he shows us how to retopologize a high-resolution, sculpted creature head to create a low-resolution version suitable for rendering and/or a realtime environment. Jonathan also goes on to bake out a normal map from the high-resolution model to the low-resolution.
Creature Head Retopology and Normal Mapping from CG Cookie on Vimeo.
