We needed for one of our university classes Linux and so I bought an external hard drive to install Ubuntu because I was too anxious to divide my current hard drive. It works just fine but I still have to learn more about it. I also bought a book about Ubuntu.
Two things I have found out that can be a bit of a draw back when you use Ubuntu are that my USB mouse and keyboard don't work on Ubuntu. I had to buy an adapter for my mouse and everytime I use Ubuntu I have to use my old keyboard. But I hope to solve this soon with some drivers or something like that. I hadn't time to fix that yet.
If you plan to learn programming I can recommend Java and you should use Eclipse (
http://en.wikipedia.org/wiki/Eclipse_%28software%29) which is a open source high quality development tool. It is almost intelligent
because it recognizes many of the mistakes you make and tells you then how to make it right. You even don't have to install it you just have to download the programm and start it right out of its folder. You can even use it on an USB flash drive!