Here is a list of cheat sheets for the Windows and .NET platform that I frequently use and I think are of great interest. Visual Studio 2005 Keyboard Shortcut References Visual C# 2005 - PDF grayscale | PDF color Visual C++ 2005 - PDF grayscale | PDF color Visual Basic 2005 - PDF grayscale | PDF color SharePoint and Office stuff CSS Reference Chart for SharePoint 2007 (Microsoft Office SharePoint Server 2007 and Windows SharePoint Services v3) CSS Reference Chart for SharePoint 2003 New Office 2007 User Interface - Word | PDF Web and ASP.
We have been doing a lot of work, on our product, with dynamic updates of web pages - you know the AJAX stuff. Most of the server side results are returned as XML and are delivered from different Web Services. Since I really like optimizations and like good and nice looking code I have been going back and forth in decision of how to return data to the client; XML or JSON.
The XML Reference Guide is a great site containing everything you need to know on XML standards, from the Document Object Model to RSS to AJAX. Each topic contains in-depth descriptions and samples wich allows you to easily read up on a technology or just have it as a reference whenever you need to. Bookmark this and save for future use.
Microsoft has release the first public release of the Windows Live Gadgets SDK, you can find it MicrosoftGadgets.com. You can also find the Gadgets Development Overview for Microsoft Sidebar for Windows Vista Beta 2 on the site. Developing Gadgets for both live.com and Microsoft Sidebar will be really easy and fun. But I see a problem with only having live.com as the only web-based Gadget host (host meaning where the Gadget can execute).