NOTE:  These steps are for IIS running on Windows Server 2003 SP2.  Steps may be different for other versions of IIS.

1.  First, you will need to fix your web.config file as I have noted in this blog post.  This is not added by default.

2. (Optional) If you are running a .Net 2.0 or .Net 3.5 website on this same server, you will need to create a new AppPool in IIS.  This is required because an AppPool can only run one version of the .Net CLR.  With .Net 4, Microsoft created a new CLR.  Therefore, you will need an AppPool for the .Net 2.0 and .Net 3.5 websites, and an AppPool for the .Net 4 websites.  NOTE:  This may have changed in later versions of IIS.

3.  Next, in Visual Studio 2010, you will need to set a number of the references of the .Web project to Copy to Local.  I had to do it for all of the System.ServiceModel references.  You may not have all of these references, and that is fine.

Then go to the Properties window, and set Copy Local equal to True.

4.  Next, you need to add a new MIME type for both the .XAP extension and the .XAML extension.

Open the IIS Management console.  Drill-down until you get to your domain/default website.  Right-click and click Properties.

Next, go to the HTTP Headers tab, then click on the Mime Types… button.

Now add the two new mime types..

Now simply publish your web project to your server, and you should be ready to go.

NOTE: This blog post does not talk about creating a Virtual Directory or making the Virtual Directory an application.  There are plenty of other blog posts that can walk you through that.  However, make sure the Virtual Directory is set to the AppPool for .Net 4(if it was required for your setup).