The official Silverlight documentation about localization gives lots of information about working with resource files, but it is kind of scant on how to actually get localized strings to show up in the UI in a reasonable way. For example, an unreasonable way would be to set the text/content properties of all the controls in a page’s code-behind file. A reasonable way is to use data binding.
Being relatively new to Silverlight development, I’ve not had the good sense to accept conventional wisdom that the Visual Studio unit test framework can’t be used to test Silverlight code. For testing view models at least, I’ve been successfully using Mstest and Rhino Mocks for a few months now.