Hi...
Yes, Ubuntu is a distribution of Linux that is free of charge and can be downloaded from their website (Canonical, the company who wrote the OS) here...
http://www.ubuntu.com/getubuntu/downloadYou can also order Ubuntu CD's from the same site and is probably easier than trying to burn a copy of it on a blank CD. To do that you will need to create an account and the CD's will be shipped to you in a few weeks. Once you get the CD's, you can install it as the only OS on your system or create a dual boot setup. Or you can do what I've done and install it in a virtual machine (VM) like VirtualBox. However, drivers will be very basic and you will see limited functionality going this route.
I have used Ubuntu 5.10, 6.06 and 8.04 and have a fair bit of experience with it. I used 5.10 (Breezy Badger) for 5 months between October, 2006 and March, 2007 as my only OS (no Windows) in part to immerse myself in Linux and to experiment with it.
Ubuntu was created with beginners (with Linux) in mind and tries to give "out of the box" functionality and simplicity upon installation. No frills, just a very basic setup to begin with. You can add programs through the Synaptic Package Manager or through regular (linux) downloads from the internet.
I don't know what your experience is with Linux but if you never tried using it before, be prepared for a learning curve!
Linux is definately NOT Windows and although the two essentially operate in the same way, beneath the hood, the nuts and bolts are very different.
The main things I can share with you at this point is that you will need to learn some Linux command line language to effectively use the OS. Linux and Ubuntu are still not entirely "point and click" OS's like Windows. If you google "Linux for beginners," there should be some links to help you out.
Also, the installation and availabilty of hardware drivers is entirely different if the copy of Ubuntu does not support them out of the box. This can include graphics cards, modems, scanners, printers, web cams
and especially wireless network cards (and chipsets!) If you are thinking about installing Ubuntu straight to the hard drive and not in a virtual environment, I would highly encourage you to research to see if your system's hardware specs are compatible with Ubuntu out of the box. Otherwise, if you can find the correct linux driver, it may be a real headache getting it installed and working correctly.
There is a Ubuntu forum where you can go for help and usually you can get answers and solutions for any problem you may have.
I can go into more detail if you have specific questions at this point.
Best Regards...
