Go get Vray for Rhino right now. You will be much, much happier. Still a learning curve, but so much better and faster.

http://asgvis.com/

i'm also trying to use flamingo for some basic shadow diagrams. anyone have any tips?

I've done many of these with flamingo but like Fog says Vray will give you faster better results unless you are using Flamingo beta 2 witch i find better than 1.1.

maxwell and brazil will work too as they all use the same module

while Vray is far superior it all depends on what you're going for.

If it's just simple shadows and sun studies why not just use RhinoRender?

because flamingo controls the sun. you could use flamingo raytrace i think you mean rather than flamingo photometric (1.1 sucks 2.0 rocks)

one other reason i would see to use Flamingo is the procedural trees, and v2 does RPCs