At some point Linux users may have to dabble with GRUB. I know this from personal experience when I trashed my Ubuntu install a few months ago.
Many people may end up re-installing Ubuntu from scratch, but such drastic measures may not be necessary if you can master a few tips and tricks using GRUB.
Hopefully you won’t trash your install like I did, but it is worth arming yourself with some knowledge of the inner workings of GRUB. Thankfully there is some excellent documentation out there. The GRUB manual is a good place to start. If you read up on some of this documentation you will learn that GRUB is more than just a boot loader.
One site I recommend is the GRUB Page. This site will show you how to customize your GRUB menu, such as adding a GRUB splash image or changing the default operating system to boot up. There is a good section on how to back up restore your MBR too. I should have read this page a few months ago!
Perhaps you want to hide the GRUB menu at bootup, or maybe your GRUB has been overwritten by a Windows installation. There are sections on that too.
GRUB is a good diagnostic tool too. When my Ubuntu install was trashed I was able to use the GRUB command line to find out information about my hard disks and partitions, and more importantly which partition contained Ubuntu. This is useful when trying to recover a borked Ubuntu system.
Another good defense mechanism you man want to consider is to create a GRUB CD-RW should things go wrong. I had problems where every time I booted up my PC the GRUB menu would fail to start. If only I had an alternative GRUB boot loader I may have had better success recovering my system.
In my situation, I ended up reinstalling Ubuntu from the live CD. But if I had learned more about GRUB beforehand it may have been a different story.