I currently have ubuntu loaded as my os. Is kubuntu better, can I load kubntu over the top of ubuntu, or do I have to start from scratch.
Any advise would be appreciated.

It's only better if you like KDE better than Gnome. Seems to me like a silly question.

Would not have asked the question if I had a large knowledge of linux still trying to learn maybe not such a silly question

With the distributions that come on DVDs or multiple CDs it is common to offer KDE, Gnome and other desktops. Quite a number of people complain about the size of the download or "bloat" on their computer. Now there are many one CD distributions which usually offer their choices of software for a smaller install. They are great for a test drive but do not show that many different options can be available on the same distribution. So you just can't win no matter what is offered.
Were the *buntu distributions to follow along the line of Fedora, Mandriva, or Suse there would be a DVD offered that had the choice to install one of the current options, all the various desktops and software, or completely user preferences on a needed base.
There are pluses and minuses to both minimal and large distributions.

This will help you load Kubuntu on top of Ubuntu:
http://www.psychocats.net/ubuntu/kde

the question should have read...GNOME vs KDE. I personally feel GNOME is much faster and stable than KDE. IF you are looking for some fancy graphics then go for Kubuntu. If not, stick to UBUNTU...like me :P

While the speed claims between Gnome/KDE, I think, are a bit exaggerated, they are there. Personally, I just hate looking at KDE.

To the OP...

Unlike the link posted above, I just used Synaptic to install the KDE environment. I've not tried to remove it, why I don't know, but its caused me no problem, YMMV. If you're having speed problems, you might want to take a look at the Xfce desktop. Very similar to Gnome/KDE, but definitely does run faster.

By the way, look at http://shots.osdir.com/ to see the respective screenshots for each OS. Might save you a little hassle of installing KDE/Xfce (Kubuntu and Xubuntu..) if you don't like the screenshots.

IGF

Another option would be to download a live cd of Kubuntu and give it a shot. You can also use Adept to download some KDE apps and give them a test drive. Most KDE apps can run under Gnome as well. I personally have always liked KDE better, but thats just me. One's not better than the other... just different.

Before making a decision to try Kubuntu give Ubuntu a few weeks of use to become familiar with it. If you still feel a need to try KDE make sure you do the same with it. It definitely takes a couple of weeks of use to make a rational decision. For what its worth, I was a SuSE KDE user foe years. After giving Ubuntu a couple of weeks I decided to change to Gnome. IMHO its more intuitive and seemed to take fewer steps than KDE to do the things I do most often. I have friends that swear by KDE and others like Gnome. Its a personal choice that you have with Linux. The kind of choice you'll never get with Windows.

To all thankyou have used a bit of advise from all.