To start making money with AdSense:
Apply, and get accepted by Google's AdSense program.
File an IRS form W-9 (or other appropriate tax form) with Google.
Generate AdSense for Content ad and link unit code for your site.
Place the code in your pages, preferably within includes.
Add AdSense web and site search boxes to your site.
Create a custom search results page that echoes the look and feel of your site.