New fans, where do I place them?

[ViioXx]

I bought two of these http://www.amazon.com/gp/product/B00066FHEW/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1 and I got no idea where to place them. I got this case http://www.newegg.com/Product/Product.aspx?Item=N82E16811119227

 

[Vic 40]

I probably would place one on the back and one on the top=against the back.