About a year ago, I was asked to do a general computer tips and tricks presentation to the Family History Center where I volunteer. It wasn't a large group but they were interested in learning. One of the topics we discussed was backing up your data. We covered the need to have multiple backup back-up copies in multiple locations. One gentleman raised his hand and said he didn't know how to back up his files except on his hard drive. He had 30 years of genealogy research and it was only on his hard drive! 30 YEARS WORTH! hoping nothing would happen in the meantime, I told him to bring it the next week and I would show him how to do a back-up. When he returned he brought his laptop, 2 flash drives, and 3 blank cds. We created multiple back-ups to be kept in different locations. Not all at home. I guess the lesson took because last week he came in with blank cds and asked me to create back-ups before he left for a trip to California!
It's not just genealogy files, correspondence, photos, finances, anything other than the actual programs needs to be backed up. Flash drives, cds (for now) and various cloud storage methods (drop-box and mozy are 2 cloud storage back-up methods) can be used. Back-up often and check your back-ups. If you don't know how to back-up your data you can google it or ask someone for help.