Here are a bunch of good links on various topics, in no particular order.
http://msdn.microsoft.com/directx/XNA/ – The XNA home. Interested in writing games for PC and/or Xbox360? This is the place to start.
http://www.thezbuffer.com/ – Home of Zman, and source of XNA related news.
http://letskilldave.com/ – The Blog of Dave “LetsKillDave” Weller, a Microsoft Employee who occasionally posts XNA related news.
http://learnxna.com/ – XNA related news and tutorials. They have a series of Video tutorials that might be handy for visual learners.
http://blogs.msdn.com/xna/default.aspx – XNA Team Blog. Get the details straight from the horse’s mouth! These are the guys responsible for XNA development at Microsoft.
http://blogs.msdn.com/shawnhar/default.aspx – The Blog of Shawn Hargreaves, another one of the XNA developers at Microsoft. He has been posting a few things about SpriteBatch performance that make for good reading.
http://blogs.msdn.com/mklucher/default.aspx – Blog of another XNA Developer and Microsoft employee, Michael Klucher.
http://blogs.msdn.com/etayrien/ – Blog of Eli Tayrien, XNA Developer at Microsoft. There has been some super-awesome technical stuff on this blog!
http://blog.3deurope.com/ – Blog of Julien Ellie, XNA Developer at Microsoft.
http://blogs.msdn.com/mitchw/ – Blog of Mitch Walker, XNA Developer. Not updated too often, but when it is, it is good.
http://www.gamedev.net – the best place for anything related to game programming
http://www.gamasutra.com – part of the Game Developer’s network (the same people who put out the Game Developer’s Magazine). They occasionally have some good articles about Game Development that appear in the Game Developer Magazine, but online. That, and the latest in the business behind a lot of the game development companies.
Other Interesting Stuff
http://www.hackaday.com – a rather interesting website dedicated to hacking/modifying things. It isn’t necessarily about computer hacking or being destructive. It is more about modifying things to do things that they originally didn’t intend to.
http://www.engadget.com/ – A site dedicated to upcoming products and other Tech news. Updated several times a day!
http://www.tomshardware.com/ – Some of the best hardware reviews on the web. Their reviews and graphics card comparison charts are amazingly helpful when choosing a new graphics card.