General Resources:

https://www.dreamspark.com/default.aspx - If you are currently a student you can have free access to Visual Studio 2008 Professional (if you haven't already downloaded it from School), along with a bunch of other useful Microsoft products and applications

http://experimentalgameplay.com/ - A great Indie game website with user submitted games based on discovering new forms of gameplay, each game is made in less than 7 days and based around a common theme, great source of inspiration

http://www.igda.org/ - The International Game Developers Association, there is a Boston Chapter as well.

http://creators.xna.com/en-US/education/gettingstarted - Check out 2D and 3D tutorials using C# and the XNA Framework. Also check out the education catalog under the education tab; that's where all the samples are.

http://creators.xna.com/ - Download XNA (Latest official release is 2.0 Refresh, Latest beta is 3.0 beta [Visual Studio 2008 Pro/Express(free) only])

http://msdn.microsoft.com/en-us/vcsharp/aa336809.aspx - Learn more about C# from the people who develop the language, and read the documentation.

http://msdn.microsoft.com/en-us/xna/default.aspx - XNA Documentation available online

http://www.codeplex.com/WiimoteLib - Managed Wiimote library written in C# by Brian Peek. This is pretty stable at this point, and is easily integrated into projects.

http://www.softimage.com/products/modtool/ - SoftImage's XSI Mod Tool, a 3D model creation package that allows you to export to formats that XNA will be able to load. It takes a lot of work to get good in this.

http://www.microsoft.com/downloads/results.aspx?freetext=gamefest&productID=&categoryId=&period=&sortCriteria=popularity&nr=20&DisplayLang=en - Gamefest Presentations. Developers talk about how to get the most out of features in the framework.

http://www.drunkenhyena.com/cgi-bin/directx.pl - DirectX tutorials, They have managed and unmanaged code here, but nothing related to XNA. The tutorials will still be applicable to development, as XNA is built upon DirectX.

http://www.directxtutorial.com/ - Great Direct X tutorials using C++, reccomended for more proficient programmers.

http://www.gamedev.net - Lots of game development resources and forums, where people can help you with problems encountered a long the way.

http://www.flipcode.com - Not updated anymore, but they have a large article archive which is useful. Nothing related to C# and XNA, but useful concepts that can be applied in any language/API.

http://blogs.msdn.com/xna/ - XNA Team blog. The people who write the framework give news and updates here.

http://www.ziggyware.com/news.php - Lots of articles and resources dedicated to XNA.

http://blogs.msdn.com/shawnhar/ - Shawn Hargreave's blog. He works on the XNA framework, and worked on a bunch of Microsoft games like MotoGP, a LIVE launch title.

http://bittermanandy.wordpress.com/ - This isn't really updated anymore, but this guy used to work at Rareware, and has a lot of cool stuff to say about helpful development tools and the process of development.

http://msdn.microsoft.com/en-us/directx/aa937788.aspx - DirectX SDK (Various Development tools and sourcecode with examples [Semi-large download])

http://www.codeplex.com/FarseerPhysics - Physics engine written in C#, can be used with XNA and Silverlight (In browser)

http://www.gameprojects.com/project/?id=e68f3464c4 - XNA Framework 3rd party GUI library (may be dead at this point, but it's usable/upgradeable)

http://www.xmission.com/~legalize/book/download/ - Free online book written by a DirectX MVP. He knows what he's talking about, but he uses DirectX and C++. Lots of similar concepts, so it's useful as a resource for XNA dev.