If you are about to start working towards the Security+ IT certification from CompTIA, I would strongly recommend downloading the exam objectives from the CompTIA web site. However, below are my study notes, mainly, so I always have the information to hand, but they may be of use if you are planning on taking the exam yourself at some stage. They should help you get started.
- Network Security
- Compliance and Operational Security
- Threats and Vulnerabilities
- Application, Data and Host Security
- Access Control and Identity Management