Configuring a WIndows 8 / safe-boot laptop for dual-boot Linux use

I have a new assignment coming up which means I will be spending a lot of time on customer sites, and so I decided that it was time I got a new laptop. I saw a great deal on an HP Pavilion ???? and so I bought it. Although I'm an open-source advocate, self-employment makes me realistic enough to realise that there are certain applications which customers insist I use (e.g. Microsoft Word) or for which there is no credible open-source equivalent (e.g. SmartDraw).

Typically in the past I've configured my laptops to be dual-boot Windows and (usually Ubuntu) Linux, allowing me to do customer work using the Windows incarnation and Linux for everything else. Sadly the new laptop runs Windows 8.1 and also has the UEFI/safe-boot BIOS on it.

This post explains how I configured my new laptop to be dual boot. These steps worked for me and are provided in good faith. But they come with absolutely NO warranty whatsoever: if you end up turning your laptop in to an expensive door-stop then that's not my worry.

1. So the first thing to do was to generate a recovery disk which - if things went horribly wrong - would at least allow me to restore the laptop back to its factory state. It is really important to do this. Seriously. The HP laptop ships with a recovery partition predefined on the disk, and generating the recovery disk on the HP is trivially easy and essentially involves transferring the image from the disk to a 32 GB USB drive which is now safely in a drawer.
2. The recovery partition predefined on the HP Pavilion is removed as part of the process of producing the recovery disk. This left space at the top-end of the disk. I then used the disk-management utility in Windows 8.1 (right-click the Windows icon on the bottom left of the screen) to shrink the main (C:) partition to allow sufficient space for Linux to reside comfortably.
3. Again using the Windows disk manager I split the available space in to two partitions: one for swap-space (16 GB) and the remainder for the Linux file systems. When you do this I recommend you don't format the new partitions or assign them drive-letters.