Generating rock/stone texture

Hi guys

I bought the Wow-book (maybe you heard of it) and tried the "Textures and backgrounds" tut in it, but no success.
How do I make a good stone texture, apparently I have to use difference clouds with some lighting effect?

the easiest way i get a stone texture is ..

Chose your colours, then Render > Clouds

Then i do Render > Lighting effects. Change the direction of the light to light the whole pic, and put a texture chanel on. Red, Green or blue should be chosen.

I gave you a pretty vauge description, but i hope it will help you in some way

Thanks a lot, I'll give it my best shot! Of course, Corel Photopaint has some terrific textures also, but alas...