Yes, it is possible to set up a dual-boot configuration with Windows and your favorite flavor of Linux. I am currently running Kubuntu 7.04 (Ubuntu with KDE as the desktop environment rather than Gnome), XP MCE, and Windows Server 2008 B3 on my XPS 400. Before you decide to install Linux, I would suggest booting using a live CD. A live CD will allow you to boot into Linux, play with it all you want, then restart back into Windows without ever changing your system. If you decide you want to install it, there's a link on the desktop to do so. I would recommend downloading the latest Kubuntu live CD here: http://kubuntu.com/download.php If you want to install it, you'll have the option to keep your current OS and have the installer set up Kubuntu on a separate partition. As you dig deeper into Linux and want to do things like read/write to your Windows partition, view Windows PCs on your network, or install Compiz Fusion, Google will become your best friend :) Have fun!

The file you're going to download is in .iso format. You'll need a program like UltraISO or CDBurnerXPPro to burn it to DVD. With UltraISO (what I use), you just right-click on the file and choose UltraISO > Burn to Disc. Once it's on a DVD, you just pop it in, reboot, and choose the Kubuntu option. You can play as much as you want, but remember that changes you make will not persist after you reboot.

It's likely that your computer's BIOS is not configured to boot from CD/DVD. You'll need to change the boot order in the BIOS. To do this, you'll need to reboot and press F2 at the Dell logo screen. That will get into System Setup. Change the Boot First Device to CD/DVD, save changes, and exit. It should load the DVD now.

At this point, I would suggest hitting up google for:
bin/sh: can't access tty; job control turned off

I searched that phrase and found lots of other people with the same problem. Seems to be a hardware compatibility problem. Google it and post your fix if you find one.

I am sorry you are having troubles getting kubuntu to load. Like I said, it sounds like a hardware issue. I am barely past being a linux n00b myself, so I'm not much help to you. Everything I know I've learned by hitting up google and the miscellaneous linux forums. Just about every tweak I've had to do seemed complicated at first, but soon got easier.

If you want to run linux, you're going to have to be willing to spend hours scouring the web for information. Working with linux is quite different than working with Windows. Personally, I don't mind. Have fun :)