Visit my blog undev.spaces.live.com. On my Tools I Use pane I have number of open source projects that you can learn from. Also Scott Hansleman has been doing a series lately called weekly 'The Weekly Source Code' lastest one is here (http://www.hanselman.com/blog/TheWeeklySourceCode22CAndVBNETLibrariesToDiggFlickrFacebookYouTubeTwitterLiveServicesGoogleAndOtherWeb20APIs.aspx)

There is also Codeplex, Code Gallery, Google Reader (subscribe to some blogs there are tons of them), Google Code Search, SourceForge, 2008 Virtual Launch, All the various new stuff for VS 2008, and the list goes on. I started keeping a list myself at del.icio.us.