Click 'Edit my site' and on the SiteMaker toolbar, select 'Edit' –> 'Organise pages' (only in advanced view). This will load the 'Pages' panel. Once the panel has loaded, you can change the order of the pages by selecting and dragging the pages using their drag handle. You can also access this feature in both 'basic' and 'advanced' view using the 'Pages' icon on the toolbar.