Welcome to the other side of the OS or as i like to call it the light side. You have some very valid questions that i will do my best to answer.
Whats the difference between Ubuntu/Xubuntu/Kubuntu? These are all esentially the same thing.
Ubuntu is any OS that is run using the gnome GUI or Graphical User Interface. This GUI has its pluses and it minuses. It is similar to the way a mac OS is set up.
Xubuntu is a scaled down version of Ubuntu. It was created to run on older systems like a P3 with 128mb of ram or even less.
Kubuntu is basically the same thing as Ubuntu except it is run with the KDE GUI. I will talk more about this later.
What is Gnome or Debian? Well, first let me break this question down into two parts. The first being what is Gnome? As i mentioned in the last answer
Gnome is a GUI, it is the default GUI for a lot of Linux OS's. It looks similar to the mac OS but still has many defining features. You can take a look at it
here.
KDE as mentioned above is another GUI. This one is more closely related to the windows setup. You can see screenshots of it
here.
The second part of your question, is about
Debian. Debian, is in it's own right a distro. It is one of the more complex of distros, and as such many other distros have barrowed bits and pieces from it. Ubuntu, is based on Debian, so that is where you might have heard about it.
Is openSuse another distribution? If so, what does it mean to run Gnome in openSUSE? Yes
OpenSUSE is another distro, it can be found
here. The other part of your question, yes, it can be run with Gnome, or KDE. It is all up to your liking.
Are these all linux based operating systems? Yes, all the OS's that you have listed are Ubuntu/Kubunt/Xubuntu, OpenSUSE, and Debian.
Which do you prefer and why? Well, for a beginner such as yourself, I would recommend that you start with something like Ubuntu, or Kubuntu found
here. Myself, I have been using Ubuntu for a couple of years now, and if i didn't have to use windows for some of my school work then i wouldn't. I have everything that i need and then some in Ubuntu. Besides Ubuntu, I have dabbled a little bit in OpenSUSE, but didn't use it to long, becuase I move on to RHEL, or Red Hat Enterprise Linux. This is a distro that unlike many distros, isn't free. I had to buy it. But I was looking to move on to other file systems. Ubuntu uses a .deb file system, do to it being a debian off-shoot. RHEL and all Red Hat off-shoots use .rpm file systems. I really am starting to like it and it likes me too, I think.
So in closing i hope that I have answered all the question that you have posted. If you ever have a question you can always im me on AIM or YIM. I am always on, but not always around.
Now, as for what xtremezx2 said, let me just clear up a couple of things for you so that you don't go informing others with the wrong information. I just wanted to let you know that beryl doesn't exist anymore. Now before you jump on me, let me explain myself. About four years ago there were two programs, compiz and beryl. Many people new about beryl and used it and it was a great program. It creates a cube of desktop enviroments for the user to use, and then allows you to change between them. However about 1.5 years about beryl was taken over by the people that created compiz, and thus the program compiz-fusion was created. It works the same as beryl but with a different name.
Cheers!
