Depending on the distro and type of wireless card you have, it may work "out of the box".
Ubuntu is *very* good for wireless cards "just working", I've heard. Ubuntu has a live-cd version, so you should be able to give it a go w/o destroying your HD.
You may have issues, though, if the wireless card manufacturer (I'm looking at you, Broadcom) won't release specs to code a driver for. My laptop has a broadcom wireless card (which I believe some Dell's use [I know they also use Intels sometimes]), and I had to use a program called ndis wrapper (or ndis *something*), which takes my Windows drivers for my network card and uses them in Linux. It didn't work 100% (some features, like ad-hoc mode, weren't available), but it did alright.
Others may have more ideas... Good luck!
p.s. could you please edit your original post and change it to "Wireless Network on Linux" or "Linux - Wireless Network - Dell Laptop" or something so people can identify it more easily? please?
