Well, I just received a new laptop at work and our IT department put their standard Windows XP image onto it. I decided I wanted to be able to also run Linux on this machine.
Step 1: Before I even logged into Windows for the first time I rebooted off a Partition Magic CD and shrunk the Windows partition to half the size of the 93 GB disk. I then added a small 2GB FAT partition where I will be able to share files between Linux and Windows. The remaining space I left unallocated.
Step 2: I logged into Windows got on the web and downloaded the latest Ubuntu ISO which was 6.06 LTS (Dapper Drake). And burned a CD.
Step 3: I rebooted off the Ubuntu CD and clicked the install icon on the desktop. I chose the option to use the remaining empty space (not overwrite whole disk). After the installation completed and I rebooted, everything worked fine. By default it boots into Linux, but there is an option to choose Windows instead.
Step 4: I did a little customization. I used the Applications->Add/Remove menu item to add Thunderbird which I am more familiar with than the Evolution mail client that comes with Ubuntu. I also used this nice graphical installer to install Emacs which is of course the One True Editor.
There, that was not too hard.