Ubuntu is one of the most popular Linux distributions for users who are new to Linux, and another release is slated for June. In the mean time don’t be afraid to test out the beta version of their new operating system which you can get in multiple flavors: Ubuntu, Kubuntu, and Edubuntu.
The differences between each of the builds is not that big. Ubuntu started out using Gnome and that is what it is popular for. Then there were many people who wanted the KDE environment so they created Kubuntu. Edubuntu stresses the ability to freely modify the software until it works exactly how you want to. I know that I didn’t go into great detail about the differences of each build so if you want more information then please refer to the homepages that I have listed below.