In case you haven't heard, Microsoft released Visual Studio 2008 and ASP.NET 3.5 today. The Standard, Professional, and Team Systems versions of Visual Studio 2008 are available for download to MSDN Subscribers. For those without an MSDN Subscription, you can download the free Visual Web Developer 2008 or, if you prefer using Notepad or some other IDE, you can download just the .NET Framework version 3.5 runtime.
Scott Guthrie has a great rundown of the new features in Visual Studio and ASP.NET 3.5. Paul Andrew recently blogged about a downloadable poster of commonly used types and namespaced in .NET 3.5, which is worth checking out. And there are a slew of ASP.NET 3.5-specific videos now up on www.asp.net.