milw0rm.com hosts many security-related videos and papers for free:

[Papers]
Lateral SQL Injection: A New Class of Vulnerability in Oracle
Security Implications of Windows Access Tokens
802.11 Attacks

[Videos]
Packet sniffing with Ettercap (arp spoofing basics)
Anonymous Voice Vlan Hack
How to Make Files Undetected by AVs
Howto using aircrack-ptw WEP cracking tool
Advanced Mysql Injection in Joomla