Hi
There are lots of different online / web backup services available and a number of them now offer unlimited data backup for 50 - 60 US dollars per year.
In general they require you to install a small application that runs in the background on you PC or Mac. You start off by telling the software what data you want to back up or you let it make that choice for you.
Once you have set it up the system is very much 'fire and forget' (at least with most of the products). The first backup takes quite some time as the software tries to only upload data when your computer is idle. This can take between a few hours and several days but you don't need to leave your computer switched on - it will just start and stop backing up as and when it can.
After the first upload the rest is easy. The software watches out to see when you make changes to a file or add new ones. It then waits for a 'quiet' moment and uploads the changes so the uploads are small and pretty quick.
There are lots of things to look out for depending on what sort of stuff you are backing up.
Some web backup providers set a maximum single file size so you need to check this if you have big media files. Most allow backups of all file types but generally exclude a backup or a backup (like backing up your Apple TimeMachine backup file) but some let you choose anything you like.
If you have USB sticks or external HDDs then check what can be included. Some support USB attached devices but not network drives and some allow both whereas other allow neither.
There are some advanced features available also. For example - some product can handle limited versioning which is great if you are a web developer. One or two can even act as a shared network drive so you can sync between machines and share your files as well as backing them up.
I hope this information helps but if you would like to know any more then please let me know and i'll do my best to answer. I also have some more information on
Web Backup Guide
Kind Regards
Chris