I agree with the recommendation above for Acronis True Image. I have the same configuration you do - two hard drives in each PC. One is 'active', one is mainly for backup. True Image backs up the active drive automatically every night, and I periodically make a separate backup to DVD disks. Twice I've had system crashes and had to restore the system from the backups. Both times it worked flawlessly.
p.s. - I tried Norton Ghost and didn't care for it.
Another vote for Acronis True Image. It's a life saver.
Tier your backups. Use the Acronis scheduler to perform a rolling 7 day backup on an external hard drive. Then, say, once a month, archive the Acronis backup of your choice off onto DVDs. Acronis will segment any of its backup file into CD- or DVD-sized chunks. Vary this scheme to suit your situation, but it pays to have a semi-permanent archive of your backups.