Best Time To Take BSN True-Mass?

I know there's such a thing as the "muscle building window" where your muscles are building and repairing themselves. I was wondering when the best time to take BSN True-mass is? (post workout, pre workout, both?) Also, I have amplified Creatine 189 from GNC, would that be a smart thing to add to the BSN? Or is that just not even necessary? Also, I know there are other BSN products that you're supposed to take with this. Are those necessary as well? If so, which ones would you most recommend besides True-mass?