First of all welcome to the forums. I you are correct, general consensus if that Prima Guide is poor, so much so mine was on order from Amazon but I cancelled it due to such bad press.

http://www.gamespot.com/features/611...%20war%20guide

I nice free, online guide for you.

But I suggest you play the tutorial if you havn't already, then start a quick short campaign while you learn the ropes. I learn whilst playing, set it all on easy so you can just concentrate on learning how stuff works.