Fork bombing attacks, like other dangers, can wreak havoc on a system if you aren't careful. Every angle that isn't covered could in fact be the most vulnerable resource to a potential cracker. Here you get a quick overview on what needs to be done to make the most of your protection:
Limiting user processes is important for running a stable system. To limit user process just add user name or group or all users to /etc/security/limits.conf file and impose process limitations.
If you need to set up secure website connections, this HOWTO is what you need. IT's focused on Debian but will help no matter what distribution you may be using.
This how-to is Debian specific but could be ported to other distributions since the concept is the same. In order to use TLS Extensions we have to patch and recompile apache2 and recompile OpenSSL with the enable-tlsext directive.
If you are going to use this HOWTO, you may want to check out their "Perfect Debian" HOWTO as well.
Here, Peter Bieringer at The Linux Documentation Project goes over keeping remote access desktops secure with IPv6.
Constantly updated, this is a great resource to keep in your bookmarks, as it is one of the most comprehensive HOWTO's you can find.
Highly recommended for anyone looking to understand the in-depth world of IP.