Search smarter with Apache Solr, Part 1: Essential features and the Solr schema
http://www.ibm.com/developerworks/java/library/j-solr1/index.html
http://www.ibm.com/developerworks/cn/java/j-solr1/
Search smarter with Apache Solr, Part 2: Solr for the enterprise
Administration, configuration, and performance
http://www.ibm.com/developerworks/web/library/j-solr2/
http://www.ibm.com/developerworks/cn/java/j-solr2/