Re: Placing Adsense on site
There is no reason why this shouldn't work, so long as:
1) You have a Google Adsense account
2) You copy and paste the code EXACTLY as they give you
3) You don't try and place more than the allowed amount of block adverts on any one page.
Now, occasionaly I have published before and my adsense hasn't shown. This can sometimes be down to Google and not you. Have you tried leaving it for a day and seeing if it appears?
I also just noticed in your post above that you are trying to preview it... Sorry... try publishing it! I don't think it works on preview all the time.
Don't aim for success if you want it; just do what you love and believe in, and it will come naturally.