I would say you probably won't see a huge difference in temps with the added fans, at least not on the cpu given the stock cooler. I would say front=intake, side=intake, rear=exhaust and if you have space under your case then put the psu fan facing down.
But that said I think the best thing would be to upgrade the cpu cooler maybe something like this Newegg if you don't wanna spend a lot. But honestly the temps you are seeing at idle aren't terrible. What kind of temps do you have at load?