To serve ads on your mobile site or Android app:
Log in to your account at www.admob.com.
Click the Sites & Apps tab.
Click the Add Site/App button.
Select a site or app type.
Fill out the required information in the details section.
If you are registering an app that has not yet been released, you may leave the field blank or enter a placeholder. Please fill this information in later, once your app is live, by editing your app’s registration.
Choose a category or channel that best describes your app or site.
Provide as detailed a description as possible for your app or site.
Click Continue. You will be taken to a page that allows you to download our site code or the appropriate native app SDK.
If you are developing a native application, you are required to use our SDKs for your platform. We do not support integrating or modifying our mobile site code to display ads within native applications.
Android, iOS and Windows Phone 7 app developers should take advantage of the detailed documentation on our Google Code site here and developer forum here.