German, but very easy and effective
and Google of itself also offers a search engine (http://www.google.com/intl/en_uk/sitesearch/index.html)
Includes unlimited site pages & PDFs.
Free version has text ads on results page.
Paid version has no ads.
Sign-up, paste the code they give you into your HTML.
Allow them to index your site (usually within 24 hours).
Customize the results page.
Limit searches to the web, your site only or both.