I might be a good idea to try 1 or 2 live CDs to see which distro suits you. Knoppix and Ubuntu/Kubuntu may be a good place to start.
There are a few places that sell the downloaded CDs and DVDs such as CheepLinux
The 2 hardest things with modern latops are the wireless chipset probably won't work out of the box and you may need to install a package called ndiswrapper to install your windows wireless driver. The next is widescreen laptops based on intel and several other graphic chips need a small bios hack run before the GUI starts to make use of the widescreen.