If you have a modem, be sure that the surge suppressor includes a phone jack and plug your modem into it. Almost all of the surge related damage that I've seen has been caused by lightning running in on the phone lines.
Depending on the size of your hard drive, I'd suggest a tape backup. It's the cheapest way to archive large amounts of data. Burnable DVDs would work as well, but hey're still pretty expensive.
Well actually you are right and wrong. No there are no viruses that I know of that have the ability to destroy a Motherboard by force, however there are quite a few that will reprogram your EEProm, CMOS insert their own code and stop your motherboard from functioning,wipe every hard drive you install and just cause general weird problems
A little advice from a tech that has learned the hard way these many years,>>>>Legal mumbo jumbo(I am in no way endorsing the repair of any system by a non qualified tech)<<<< Before you replace that MB try disconnecting all drives except for the floppy, boot the machine using a write protected disk and reburn the EEprom, CMOS. Check with the manufacture for the program-disk to do this with. I have even seen malicious code in Video card EEproms before. Intelligence + Commonsense = Unbeatable logic.
Yes. If the power supply and monitor are not damaged, then the surge is most likely on the phone line, or over the cable if you have a cable modem.
SO9