I've become a fan of podcasts and all the content they offer. Or, maybe I'm too cheap to pay for content.
If you are a student of history at all, specifically war, this guy does some good stuff. Current content is free with archives costing a small fee.
He does a commentary audio blog on current stuff called Common Sense and another in-depth historical series called Hardcore History.
The last series he did was on WW1 called Blueprint for Armageddon parts 1 through 4. Each episode is 3-4 hrs and it's riveting stuff.
Dan Carlin website
http://www.dancarlin.com/disp.php/hharchive
You can still get the Genghis Khan series, Wrath of the Khans for free.