Fluidsym on complex mesh: Newb wants to jump in the deep end.

Hi all,
I’m relatively new to blender, I’ve used it as a utility and little else, but I am very excited about the things I see.
My question is in regard to the suitability of blender for my task. I have a collada object which was rendered from a digital elevation model of a watershed in colorado. The model is pretty complex. What I need to do is illustrate the basic function of a watershed: directing rainwater into rivers and lakes. What I would like to do is to create a fluid simulation wherein particle raindrops hit the surface and collect as mentioned above. I’ve gone through the basic tutorial on fluidsim and I believe I understand the basic objects. Can anyone point me in the direction of further tutorials, or give me a basic rundown on how to get started?

If you want a commercial video tutorial
http://www.cmivfx.com/Blender3D_Training_Tutorials/b_fluids/default.aspx

Richard