You have a great site there to start off Do you use channels to monitor your three ad format? Which is the better performing ones? I would shift the right adsense ads (120 x 600) to above fold and if need be, remove the one on the left if its not performing. You might also want to write some longer articles and embed squarish adsense ad format on these articles. Good luck!
Looks ok to me on the placement. Maybe shorten the page length on your home page so that visitors could scroll back to the top and notice the ads.