The Institute for the Study of War (ISW) has a new blog that allows you to follow important developments in Syria. There are lots of maps, descriptions of fighting and military movements, and details about Bashar al-Assad's response to all the events.
ISW, founded in May 2007 by Dr. Kimberly Kagan, was established to provide real-time, independent, and open-source analysis of ongoing military operations and insurgent attacks in Iraq. General Jack Keane (U.S. Army, Ret.) is the Chairman of ISW's Board of Directors.
Dr. Kagan's husband, Frederick Kagan, is the Christopher DeMuth Chair and Director of the Critical Threats Project at the American Enterprise Institute (AEI). Along with his wife, Frederick Kagan is a faculty member of the Hertog War Studies Summer Program in Washington, DC, an intensive two-week program run by ISW.
Here is a previous Think Tank Watch post on what various think tanks are saying about a possible US intervention in Syria.