The Ghost Brigades by John Scalzi

This is the second novel in Scalzi's highly acclaimed "Old Man's War" series and even though I haven't read the prequel I am pleased to say it stands on its own. Scalzi's universe is a belligerent place and everybody species is either openly at war with its neighbours or plotting secretly against them. In order to survive and indeed thrive the CDF representing humanity has developed an army of bio-engineered super soldiers. The elite of the elite are known as the ghost brigades: special forces with bodies that are grown at a vastly accelerated pace and whose minds come from dead recruits. When a brilliant scientist defects to enemy who is planning a genocidal war against humanity the only clue left behind as to his motives is a computer snapshot of his mind.  This conciousness is imprinted on a unwitting new ghost brigade soldier in a risky attempt to try and find out what humanities enemies are planning.  It falls under the heading of military Sci Fi but you certainly don't have to be a military nut to appreciate this story. Good stuff. Highly recommended.