I've posted close to 50 posts on Security+ topics so though it'd be worthwhile to list many of them to help you in your studies.
This blog lists some of the topics. If you want to see a few practice test questions, check out this blog.
Least Privilege
Mandatory Vacations
Separation of Duties
VOIP Risks
Vulnerability Assessments
CompTIA Makes it Official - No Recertification until 2011
Hashing
The Security Triad
CompTIA Security+: Get Certified Get Ahead: SY0-201 Study Guide
Promiscuous or non-promiscuous
Protocol Analyzers
Faraday cage
Symmetric vs Asymmetric
What's in a CRL
Identity proofing
RADIUS
Redundancy
CompTIA Security+: Get Certified Get Ahead: SY0-201 Study Guide
Phishing
Dumpster diving
Piggybacking or tailgating
Impersonation
Social engineering
Disk redundnacy using RAID
DoS and DDoS attacks
Well-known ports
Understanding ports
Biometrics used in authentication
Digital signatures
Use of virtualization in security
CompTIA Security+: Get Certified Get Ahead: SY0-201 Study Guide
Encryption basics
Qualitative risk assessment
Bluetooth concenrs
SSL, OCSP, vs CRL
Three factors of authentication
Quantitative risk assessments
Intrusion detection systems (HIDS and NIDS)
Good luck in your studies
Darril Gibson