I am trying to insert ad sense and i am having a problem.
Any good web sites to help me out?

The Google AdSence pages should have more than enough info for integration of the code.

I assume you are using design view?

You will need to copy the code that Google provides you into the "code view" part of Dreamweaver.

Whats your problem?
In which part do you have problem?
Have your website approved for using of Adsense?
If yes, you should not have any problem, Just go to your adsense account and Generate codes in your desired format and color , then copy that code to your website. Just it.