I can present multiple pages in Silverlight using
Content = new DetailsPage();
However is this can be confusing to a user who may not even know the page is in Silverlight and would be expecting to hit the back button on the browser. Obviously I can add my own buttons but this doesn't seem right.
How can I allow "normal" browser navigation using the back/forwards button?
You should really formulate a question.
I'll assume that you want to know how to achieve multi-page navigation with browser back-button support.
There one simple answer, which is to use Silverlight 3 where it is supported out of the box, as well as in-app navigation using the address bar.
Release date is set for july 10, so there's not much longer to wait. Be careful, you cannot at the moment install both Silverlight 2 and 3 on one machine, and there is no end-user plugin available (only developper runtimes, to install manually).
In Silverlight 2, you can still handle navigation. It's just a more manual process.
Call
HtmlPage.Window.NavigateToBookmark("blah");
to add the "#blah" to the end of the URL. Call
string bookmark = HtmlPage.Window.CurrentBookmark;
to find out where you currently are. People are also tying into jquery/Asp.net AJAX libraries to use their navigation support.
In Silverlight 3, you can use the Navigation Framework to do some of this automatically. File->New Project->Silverlight Navigation Project.