I am creating a theme now that will have adsense links in the header menu (right below the header -- not sure of correct terminology) and one to the left side before content begins. These will be very close to touching. Is this ok? Could I conceivably have three ads that all touch each other? Thanks!
The more adsense you have on a page, the less you get per click. In my experience, less adds is better. I use one big block just before the main content on the page.