Links on this page are to a variety of news sources directly from the Department of Defense. Great for timeliness -- a lot of what you will see on a particular day will be repeated by the nightly news and newspapers the following day.
defenselink.mil The mother-of-all-DoD-news-resources. From this homepage, you can wind your way through news and research websites for every tiny corner of the military on the world wide web.
DoD Newsfeeds From this webpage, you can subscribe to receive e-mail notices of news releases, contract awards, press advisories, and news transcripts. Volume definitely picks up during military actions.
FedBizOpps Search This isn't DoD specific, but you can search all of the business opportunities posted by the government. It's the equivalent of the old Commerce Business Daily (CBD) notices.