Creating dynamic heightmaps

I would like to create heightmaps on the fly, well every time i run the prgram so the terrain is different.

I was wondering what i need to create one?? do i only need to have the coords of each point?? and how many points should i have?


An easy way to start is to import a grayscale bitmap for a height map. Use each pixel as a vertex in a grid made of triangle strips. When you are rendering the heightmap correctly, look up Perlin noise on the web.