This tutorial will help you to include google adsense custom search into your wordpress blog.
It’s a little complicated The idea of this tutorial is display google custom search results as a page of your blog. This will improve your revenue and blog’s usability. I recomend you to do a full blog and db backup.
Wordpress includes 2 file for search: search.php and searchresults.php. In most cases you can integrate Google custom search by editing of these two files, in other cases you must create a custom template for search results.