JasperReports

Embeddable open source Java reporting library
JasperReports is the world's most widely used open source reporting engine.

Tips and Tricks
http://fecplanner.com/jasperreports/docs/tutorial/index.html

Download iReport from jasperforge
http://jasperforge.org/plugins/project/project_home.php?projectname=ireport
Articles on JasperReports

Reports made easy with JasperReports
http://www.javaworld.com/javaworld/jw-09-2002/jw-0920-opensourceprofile.html

Tutorial on Generating Reports and PDFs From a Web Application Using NetBeans5.5
http://netbeans.org/kb/55/vwp-reports.html

Basic Jasper-Report-Tutorial
http://www.docstoc.com/docs/2139263/Jasper-Report-Tutorial

To Browse Forums-Question and Answers
http://jasperforge.org/plugins/espforum/browse.php?group_id=102&forumid=103