A good online backup solution is something that you setup once, and forget till the day you need it.
Personally I use a service called CrashPlan, and I can only recommend it. You can decide to use a different tool, the ideas highlighted here will probably still apply. CrashPlan is composed by a multi-platform application (available [...]

You do have one, haven’t you? If you don’t, you might find what follows interesting. I will describe my own backup strategy, which is probably an overkill for most users’ needs, but will give you an idea of some available options and the corresponding “recovery time”. I mention the recovery time because for me it’s [...]