There are many best practices for Security. Help curate resources for the community.

Tools

• Tor
  • Security in a box guide to using Tor
• Surveillance Self-Defense: Defensive Technology
• The Guardian Project
• Mozilla Firefox Privacy -Security Add-ons
  • Security in a box guide to Firefox security add-ons
• Privacy script: a virtual machine that works like a live cd. It provides a minimalist linux desktop, but nothing you do persists. If you reboot, you start on a clean installation.
• Collusion (Mozilla Firefox add-on). Track who is tracking you
• Open Web Application Security Project (multiple languages).
• Report unavailable websites with Herdict

Other Resources:

• SaferMobile (via MobileActive)
• Access Now
  • Defense Against Denial of Service Guide (DDOS) (Mulitple Languages)
  • Protecting your Security Online (Multiple Languages)
  • Additional Policy Activism Resources
  • Digital Security and Privacy for Human Rights Defenders(via Frontline Defenders)
• New Tactics in Human Rights
  • Being Well and Staying Safe: Resources for human rights defenders(June 2011)
  • Staying Safe: Security Resources for Human Rights Defenders (July 2010)
  • Well-Being Security for Defenders
• Security in-a-Box (Multiple languages)
  • How to remain anonymous and bypass censorship on the Internet
  • How to protect your information from physical threats
• Resources for Online Anonymity, Encryption and Privacy from Herdict
• SMS Privacy Tips for Election Monitoring And More
• Non Violent Struggle -- 50 Crucial Point (Multiple Languages)
• Hints and Tips for Whistleblowers
• WARNING: Social media is dangerous (via Meedan)
• Skype security weaknesses could endanger vulnerable users
• Organize on Facebook Securely (via Movements)
• Open Net Initiative (series)
• The World's 7 Worst internet Censorship offenders 
• Network 23