I Feel Really Stupid

I have read and re-read the instructions for posting adsense ads on this site. I guess what I don't understand is where to paste the html codes. Does anyone else out there have this problem? I surely can't be the only one. I think I need to go spend some time with Einstein, Gracie and Pink. No matter how dumb I am, they think I am the smartest person in the world and right now, my ego needs a boost.