Remember that Autodesk MapGuide tips are here and use the right mouse button in MapGuide if you need help.
When you double-click on an annexation, you see select document sheets making up the annexation information for that annexation. Since streets go through most areas, you may need to be careful to double-click on an the annexation area itself and not a street centerline. You may want to zoom in more or turn off the Streets layer to make it easier if you have trouble.
Displaying documents brings up another browser window. You will then have one window for the request and one for documents. When you are in the document window, the browser's "Back" button does not take you back to the requesting window. After looking at documents, you can either use the "Done" button in the frame or dismiss the document window.