Battlefields Review - Bi-monthly magazine covering the history of battles and the ground over which they were fought. Site includes a small selection of articles from back issues.
G.I. Journal - Bi-monthly (and currently defunct) magazine dedicated to the US Army in WW1 and WW2. Site lists the articles printedin each edition.
MagWeb - Thousands of online articles from over 70 military history and gaming magazine titles. A subscription is required to access them, but there is a good selection of free samples.
The Military Book Review - Reviews military history books, including those covering World War II, World War I, the Napoleonic era, Korea and Vietnam.