Check out Customizing the Front Page of Your TRIBUS Ashland Theme Site For an introduction to Front Page widgets. Widgets are found in the Dashboard at Appearance->Widgets.
The TRIBUS Theme: Calls to Action widget lets you create one to three large icon-based links on your Front Page. Calls to Action can be linked to Pages on your site. If less than three Calls to Action are created, they will stretch horizontally to utilize available space.
From the widget, you can select an Icon, insert a Headline, include a Message (optional), and specify which Page should be linked to the Call to Action. CTAs can only link to Pages that exist on your site.