Security is based on three characteristics: prevention, protection and detection. Grsecurity is a patch for Linux kernel that allows you to increase each of these points.
Read it at howtoforge
This howto was performed on a Debian Lenny system. Thus some tools are Debian specific. However, tasks can be performed with other distro specific tools or even with universal tools (make).
Everything will done with root privileges. However, you can perform them with a limited account thanks to sudo and fake-kpkg tools.