Forum OpenACS Q&A: Response to Any contributions to a RH HowTo?
If you're going to deal with security, you should have a section on performance tuning (or at least specify when you are doing something for security reasons, performance reasons, or both).
More RAM, more disk spindles (nothing but SCSI for me). I always keep user accounts (home directories), web software, third party apps (databases, etc.) off the root drive. I guess one topic you might consider is mirroring the root drive (I don't do it myself). I prefer ECC memory myself, but my current motherboard (ASUS CUSL2 w/Intel i815E chipset) doesn't enable ECC (ECC DIMMS work though).