When I was a highschool youngster I was highly interested to learn programming at my best mostly because I wanted to develop games.
Future showed that my destination has gone in different direction but nostalgy built in my mind moves me to constant tracing about news to know what's going on in gamedev currently.
If I imagine a fresh-new developer with a dream like I had I managed to check some newbie startup resources with a followup path where to go if results become more and more proffesional:
Of course there is nothing new right now with XNA to announce (beside maybe v1.0 Refresh release) but for a beginner who started learning managed code with c# XNA Game Studio Express Ed. is good place to start with:
To stay tuned with XNA news I recommend: http://creators.xna.com/ XNA Creators Club Online
If you'd be interested in simple games like there are tones of for Adobe Flash - you could also check for alternatives using still in development Silverlight technology:
http://silverlight.net/ I think this technology and tools might be also useful to trace.
Back to XNA, there are also nice 3rd party tools that might help do nice products:
http://www.visual3d.net/ - Realmware Visual 3d.NET
http://www.blade3d.com/ - Blade 3D
If you continue to play with these technologies and you would like to go further I recomend to check full DirectX SDK and C# perspective to learn some basic architecture and pipeline outline and then to switch to C++ for most advanced topics: http://msdn.microsoft.com/directx/
Then I recommend to check some publications both on paper (game developer) and online (gamasutra) to check trends constantly and stay updated.
Later on I think it might be good to check some casual games developent opportunities to break into commercials:
http://www.microsoftcasualgames.msn.com/developers.htm <- here you can find some information for XBox Live game development, MSN Games development and Live Communicator games development.
I think it's a very good start to build your individual portfolio 🙂