Recovery disks became necessary for Windows users, once manufacturers stopped including OEM install CDs and moved recovery images to a partition on the hard drive. Many Windows users don't know this and find out the hard way once their hard drive dies. This model doesn't really apply to Ubuntu, you just go to Ubuntu.com and download it.
For a backup of the OS, you have a few options.
- You can just give them a standard Ubuntu disc you burned to reinstall from.
- You can make a custom Live CD/DVD to give them, tailoring languages
and applications as you like.
- You can even buy pressed CDs and DVDs from Canonical that look
more professional (this is what I do).
- Another option is to do an OEM Ubuntu install for them, but
this requires that you do most of the work and then hand them the
computer once it's almost restored.
Next you need to address how you back up their data and settings. This is usually all contained in
/home(verify this is correct, some people have weird set ups). Use the built-in Backup utility to save everything, it works perfectly and you can schedule automatic backups. Save backups to a partition on the same drive, to Ubuntu One, or to an different drive using the built-in Backup utility. Just choose which destination you want in
Settings -> Backup -> Storage -> Backup location. Make it automatic, with regularly scheduled backups run.
If you really want to make things easy for customers, you should create your own documentation with easy to follow steps and screenshots. Set everything up correctly, include clear instructions, and offer hourly paid support as an option for those that want it.
If this is all too complicated and you just want to clone the drives that has already been asked, some duplicates are here 1, 2, 3. You'll still be stuck with customers that want you to walk them through the entire process though.