Another solid shortcut from O'Reilly by Wei-Meng Lee - -check it out
ASP.NET "Atlas" is a new developer framework from Microsoft that simplifies the task of building more interactive web pages by drawing on the power of the Ajax technologies found in most modern browsers. Because of its tight integration with ASP.NET 2.0, Atlas will be of particular interest to Microsoft web developers. In this Short Cut, Microsoft MVP Wei-Meng Lee introduces you to Atlas by showing ten ways you can use the technology to improve the user experience of your existing ASP.NET 2.0 apps. There's no better way to get acquainted with Atlas than by diving into a project, so read on and let's get started.