And backup the backups, and store offline. Dropbox is private, useful for photo's/docs and I use photobucket. I don't turn my PC off though (I turn the monitor off) and have not had malware/virus problems for an age.
Another vote for Dropbox, a great, free resource. Just don't keep plaintext passwords or anything really important (that isn't encrypted) in it. Possibly its most used feature in our family is the ability to have shared folders on each others computers, it makes moving files, movies and pictures so much easier.