Using Expression DeepZoom is pretty straight forward. We start with adding a multiScaleImage to our Xaml and then pointing it at our collection 'bin' file. Generally we would take the output from DeepZoom and then input it into our web project, that we are using to build out our Silverlight application. Then we point the source to the info.bin file. In the case of the collection we built in the last sections it will look something like this:
read more at:
http://hackingsilverlight.blogspot.com/2008/04/actually-using-multi-scale-images-in.html