Hi,
Lots of article out there, what you have to do google it. few pointer:
1) make sure you aware of any patch release by vendor.
2) subscribe to vendor mailing list/linux security mailing list etc
3) since you run apache, make sure you config properly.
4) for wuftp, I suggest you run in chroot mode as only allow user to stay at their user home directory.
regards,
feroz