Want to know about Search engines.

Hi All,

I would like to read about search engines how they have been implemented. what kind of algorithms we should use. I would also like to study and implement a sample search engine. Kindly let me know where should I look for such resources or if any one can help me in this.

Lots of them available; start here: http://java-source.net/open-source/search-engines

Thanks its really useful!