Upper left and middle of any page. When you go to a page, watch where your eyes go.
Bottom of the page is less intrusive, but gets a much lower CTR in my experience.
-Allan :gl:
Try put "Google Adsense" table between "Main Navigation" and "Please Vote". You can try also put small adsense ad between first and second news (in Main Content)
i would say upper left or right - in your case, visitors need to scroll down just to see the ad, its better to have it in site when the page is loaded as is