Funny you should ask! I've got a two-part Bugslayer column coming up in MSDN Magazine that discusses how to internationalize .NET applications. The good news is that it's relatively simple to do. If you can't wait for my column, here are some URLs that'll get you going:
General Overviews: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpcondevelopingworld-readyapplicationsoverview.asp
Best Practices:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconbestpracticesforglobalapplicationdesign.asp
This was first published in February 2004