To give you some advices/hints/help I would like to know a little more about your game. You said it's a 3D strategy game. What about the camera view? Is it dynamic? Or a fixed view from top, side, etc.
Do you know how to use billboards?
What exactly do you want to know? How to make the graphics? A particle system? Explosions, fire, smoke?

Greetings,
Dirk