This plugin will detect mobile phones, and redirect to Mippin.com to display a mobile optimized version of the page.
No, the default is to do nothing other than activating the plugin and making sure your feeds are switched on (which is a wordpress default).
Yes, you go to Mippinmaker.com on your PC and type in your url of your blog. Then sign up and sign in and modify your settings in the customise settings.
Yes, you can add AdMob advertisements to the mobile version of your pages. All you have to do is sign up for Admob (at http://www.admob.com) and then add your AdMob Site ID on the Monetize Option.