The Information Systems Audit and Control Association website includes many auditing resources as well as information concerning auditing certification.
The IT Governance Institute
This website includes many resources related to IT Governance models, COBIT, Val IT, and more.
The CERT website includes many resources for securing Information Technology systems. The CERT Coordination Center is located at Carnegie Mellon University.
The website includes many audit resources and articles.
European Spreadsheet Risks Interest Group
The site belongs to the European Spreadsheet Risks Interest Group. It includes spreadsheet error stories as well as white papers describing spreadsheet best practices.