Mixture is a great advocate of backups for all occasions. I'm sure he will assist with good advice when he's able.
I've been on a jolly nice 10 day holiday somewhere nice and warm ....
Back now (although much reduced until I've cleared the loads that piled on my desk)
As I'm not sure what's needed here, I'll summarise a few gems in a nutshell until someone cares to fill me in :
(1) Three copies of anything remotely important you don't want to loose. That's three copies IN ADDITION to your live copy.... NOT two plus live !
(2) Said copies should be on three separate devices, ideally from different manufacturers, and ideally a mix of media (e.g. two HD, one blu-ray). If you want to take things one step further, look into media rotation strategies such as Hanoi or GFS. And no, RAID does NOT count as a backup copy.
(3) For anything really, really, really, really important keep one up-to-date backup copy off-site somewhere safe. And when I say off-site, I mean geographically distant off-site ... not your garden shed, not your garage, not your neighbour's cupboard.... I mean somewhere that takes
at least 30 minutes to drive to when there's no traffic ! Remember you should be encrypting your off-site backups anyway... so you can always put a copy in the post to somewhere far far away.
(4) Repeat after me.... an untested backup is not a backup.... don't forget to do your test restores guys !
(5) Don't backup anything you can re-install.... so don't waste your time backing up or cloning your operating system or your software for example ... you can (and SHOULD) re-install those clean from scratch. Another reason not to waste your time cloning is your backups will complete A LOT quicker...especially if you use diff backups.