You can simply perform regular backups.
Hardware security can be established in an easy way using a RAID system. The basic RAID1 level is cheap and efficient. It is also called mirroring. You need two identical hard drives (IDE, SATA or SCSI) and an optional RAID controler (may be software based, embedded on the mother board or PCI expansion card). Data is saved equaly on both disks (mirroring). If one disk fails, you just need to replace it without loosing data stored on the other one. Once replaced, data will be mirrored automatically. You can also use RAID 5 in a similar way, with at least 4 disks, with mirroring and enhanced storage space.