Attached Link: http://www.renderosity.com/tut.ez?Form.ViewPages=939

I wrote a small tutorial on the function editor in the Renderosity tutorial section which you can find at the link. I'm not sure if this the one you found too complicated, but it will get you pointed in the right direction. The key point to remember is that functions produce values in the range of -1 to +1. When you understand what the -1's and +1's are doing, (e.g by using an RGB color map), you can easily observe the behavior of the various noises and math functions. It's best to try and play with it with a simple model (e.g. a sphere) and then try different things. Also, the included Vue mats are a good source of examples of how to use various functions.