One site-wide contact form can be designated as the default contact form. If you choose to designate a default form, the <em>Contact</em> menu link in the <em>Footer</em> menu will link to it. You can modify this link from the <a href=":menu-settings">Menus page</a> if you have the Menu UI module installed. You can also create links to other contact forms; the URL for each form you have set up has format <em>contact/machine_name_of_form</em>.