An introduction to the process for granting security clearances for access to classified information was presented in a new report from the Congressional Research Service. See Security Clearance Process: Answers to Frequently Asked Questions, September 9, 2013.
A related CRS report on leaks and the law was also updated this week. See Criminal Prohibitions on the Publication of Classified Defense Information, updated September 9, 2013.
And for good measure, there is this new CRS report: The Potential Federal Tax Implications of United States v. Windsor (Striking Section 3 of the Defense of Marriage Act (DOMA)): Selected Issues, September 9, 2013.