I have been working with Nick Gattuccio on authoring a two-part MSDN article about using event receivers in SharePoint 2010. The first part provides a thorough explanation of what events are and how they can be developed and deployed in SharePoint. The second part provides practical examples using Visual Studio 2010.
Title: Using Event Receivers in SharePoint Foundation 2010 (Part 1 of 2)
Title: Using Event Receivers in SharePoint Foundation 2010 (Part 2 of 2)
Let me know how useful this is to you.