For a good read about 21st century warfare, and in particular information age warfare, try this article from the Atlantic.
War Goes Viral. I'm someone who has been soaking in bits and pieces about information age warfare for about 20 years, and have found Lind's various pieces on 4th Generation Warfare to be of interest and current applicability.
The article is well worth the read by anyone with an interest military affairs.
Know the battlefield, if you want to win the fight.