Nothin special, experiment and put one block under the RSS Feed and look at analytics what resolution have the most users and put the ad just like that that you hide "Google ad" sign.
Not good at all. Let me ask you a question, when was the last time you clicked an ad... dont expect people to click on your dull ads, you gotta make them attractive, you gotta make them blend. try using more image banners and 480*15 links that look like part of the site, try playing with the colours no one will notice your ads, sometimes is good to make them blend with your site but when you got a site with nothing but words, you gotta make them stand out, good luck