Generally, how a search engine work - http://horicky.blogspot.com/2010/03/search-engine-basics.html

Search engine logic - http://www.infoq.com/cn/articles/a-search-engine-scheduling-architecture-for-reference

Don't tell me everything you know - limit to specific set of datas , like ameture / professional
Ask me the next most reasonable question
Offer me to establish my search identity

http://jooto.com/blog/index.php/2008/01/05/how-to-improve-search-engines/

https://advancedweb.hu/intro-to-lucene/