Since my server was hacked I’m creating a spot where I can put all the links I’ve found to Security (and Linux Security in particular) so that I can find them when I want them.
netfilter.samba.org
www.linuxnewbie.org/nhf/intel/security/iptables_basics.html
securityportal.com/cover/coverstory20010122.html
www.linux-sec.net/Hacking/
www.auscert.org.au/Information/Auscert_info/papers.html
www.bastille-linux.org/
www.linuxdoc.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/
www.chkrootkit.org
www.lucidic.net/whitepapers/sholcroft-4.1-2002.html
Security Focus
www.networkintrusion.co.uk/
I’m sure I’ll find lots more