Visualizing a Height Field in Real time & in C#

I want to use a multidimensional array to hold vertical data (Using [x, y] coordinates to hold z data) to deform a mesh but I have no idea as to where to start going about doing this.

I know about multidimensional arrays holding vertical data but as far as using that data to change the vertices of a mesh (Lets say a plane to make it a lot simpler) in real time I don't really know where to begin. I've taken a look at the procedural generation demo but it didn't really give me any ideas other than the height map generator but that's in java script and I can barely understand it.

The reason I want to run it in real time is obviously because I want the array data to change in real time. I'm not asking for a whole lot of code (that would get rid of all the fun!) Im just asking for a nudge in the right direction.

Any help would be appreciated :) Thanks!