I have a machine that I wish to install 3 operating systems on. The systems are, in no particular order, Windows 8, Ubuntu, and Backtrack Linux. Is there some document or step-by-step guide to the correct way to partition the drive and bootloader in order to install all 3 operating systems?
General rule of thumb is "dumbest first". This means start with Windows, as its installer assumes that there are no non-Windows OSes on the disk, and it will happily wipe
So your steps are, roughly:
Alternatively, if you want to avoid any and all potential problems, get a separate hdd for the Linux bootloader, and let Windows have the other (at least as far as boot sectors go); this does mean though that you have to select the boot disk in the BIOS rather than through the bootloader menu.