Zotero

Here's a  referencing tool which is much better and more flexible than end notes. It is free, easy to use and is web-based. Here's what Zotero say about their tool:

'Zotero is an easy-to-use yet powerful research tool that helps you gather, organize, and analyze sources (citations, full texts, web pages, images, and other objects), and lets you share the results of your research in a variety of ways. An extension to the popular open-source web browser Firefox, Zotero includes the best parts of older reference manager software (like EndNote) — the ability to store author, title, and publication fields and to export that information as formatted references—and the best parts of modern software and web applications (like iTunes and del.icio.us), such as the ability to interact, tag, and search in advanced ways...'