deploying flex apps on IIS is just like deploying any other
asp.net applcaiton, your flex application is nothing but a swf file(embedded in an HTML) page, you have to follow the same process of deploying any other asp application i.e create a virtual directory, drop your flex objects into that(contents of bin/bin-debug folder) and configure IIS settings as required.
Make sure that you are dropping your cross domain file appropriately(i.e at the root directory of the data source) or else your app would show up w/o any data.
saurabh