SANS/FBI "Top 20" List of Security Issues for Win and Unix

Interesting but mostly obvious stuff: http://www.sans.org/top20/. The list contains *not* the overall top 20 security issues as they see it, but rather top 10 Windows and top 10 Unix with no relation to each other. This list is *great* stuff to be aware of and does include not only the issues but resources and instructions on addressing them. Good stuff.