Toshiba Satellite w Vista/XP partition; want Linux as 3rd partition; how can I?

[xunil]

I am taking a Linux college class that starts 28JAN12 and at the end of the 1st chapter of the book it says to install Linux. The book doesn't say which version. I keep vista and xp because I still have programs that I use each for and I want to just find the lowest amount of memory Linux version to install on my laptop and be able to also use Vista and XP. I don't have the XP or Vista disks with me and just want to be able to just add the linux on my computer and start using it. I do not know where to begin. Will u help me? thanks.

[Padre King]

Just get a livecd/livedvd of the verison of linux they want you to install. When your thru with the class reboot with the dvd removed. Nothing gets written to hard drive and you'll have access to wired and perhaps wireless network. With a little more tinkering you might even be able to access the hard drive or a flash memory card to store data from the class.
CentOS 6.3 should be a good candidate if they aren't too choosy.