The ASP.NET Resource Kit is an essential resource for any web developer whether you're already using ASP.NET today, or looking to learn ASP.NET. The kit contains step-by-step instructions for getting started with ASP.NET, free controls from third party vendors, access to great ASP.NET hosting deals and more.
Here are a couple of useful whitepapers I've used today to understand best practises for exposing Windows SharePoint Services over the Internet:
Whether or not you have been developing for the Microsoft Office System for a long time or just getting started, you may be a little overwhelmed by the number of new or updated Microsoft products available for building collaborative solutions. This article Sorting Out Microsoft's Collaboration Technologies lists the different programs that you can use as the main components of a collaborative solution.
And finally - the great news today is BizTalk 2004 RTMed. Everything should be available via the web on or before launch day, 2nd March.