Prior to installing Office SharePoint Server 2007 on any servers, you should first harden the servers per Microsoft's security hardening recommendations.
When applying security to a server, especially if you aren't experienced with server hardening, there is a chance you will break something in the process. After applying each change, test to ensure the change functions as intended and that you haven't broken anything. If you continue securing other things and determine later that something is not functioning properly, it will be much more difficult to determine which step in the process caused the issue.
After installing Windows Server 2003, you should harden your Windows Server installation prior to installing any services or applications. Microsoft has made available the Windows Server 2003 Security Guide, a freely available 250-page document that provides detailed guidance on hardening your Windows Server 2003 systems. Some of the high points of this guide will be covered, but it will be left to you to download the document and review information specific to your deployment:
You should never use anything but NTFS on your server filesystems. There is no good reason to use FAT or FAT32 file systems on servers, and their use makes it difficult—and in some circumstances impossible—to maintain a secure server. ...