Here is a great step-by-step document for creating a Network Security Management infrastructure using Snort, Apache, SSL, PHP, MySQL, and BASE installed on CentOS 4, RHEL 4 or Fedora Core – with NTOP.

Introduction from Patrick Harper, CISSP, RHCT, MCSE:

This is really a deviation from what I have done before. It will start from a minimal install of CentOS 4 or RHEL 4 and will build a Snort sensor/manager. This system will start at the command line and not have X window installed unless you add it during the install. Also you can use Fedora with very little change to this doc.

The document can be downloaded from www.internetsecurityguru.com and so can a VMWare image with the NSM completely configured.

I have personally set this up without running into any issues. I strongly suggest you pre-read the document before attempting the steps so that you understand what is required of you.