Ranked in these QuestionsQuestion Ranking
Pro Easy to learn
Pro Can be run as a service (server version) that allows deep links to individual reports or embedded with your web app as a library.
You may or may not want a server version with its own learning curve and API. With Jasper you have the option of server vs library. With either one you can whip up reports and make them available in PDF, XML, HTML, CSV, XLS, RTF or TXT format. It's not very difficult to do that with JasperReports. And there are many examples out there to learn from.
Pro Eclipse-based report designer is fairly easy to use.
Jasperstudio report designer is easy enough to grok. It is full of features for designing your reports in a wysiwyg manner.