What can I do with a lens ? How can I put adsense in it?

Tweet

Recently I joined squidoo and created two lenses. One is http://www.squidoo.com/kwanmas/ another one is http://www.squidoo.com/savethechildren/blissfulkwanmas but actually I am still figuring out how to make use of the utilities there. I don't know how to put adsense code in the lenses. Can you give me some ideas? Thanks