The Page Settings menu option provides access to page-specific options, and can be modified on a page-by-page bases depending on your specific needs.
Across the top of each page, just beneath the site's header, Google Sites reserves a space for the title of your Page. By default, the Show Page Title box is checked. If you do not want the title of a specific page to display, simply remove the check from the box.
The page title is always displayed while in Edit mode, regardless of whether the Show Page Title box is checked or not.
Also of note is the fact that - whether displayed or not - whatever is entered as the page title for your page will be the link that appears in the Navigation gadget in your Sidebar.
As you build your Google Sites website, you have the ability to create a hierarchical structure for your pages. Checking the box next to the Show Links to Sub-Pages option will display a list of any sub-pages along the bottom of the page.
Checking the box next to Allow Attachments will cause the Attachments section to display along the bottom of the page. You can enable this option, attach any necessary files and then disable the option if you would like to attach files but not display the list to site visitors. Doing this will not impact your ability to access the uploaded files if you make not of the URLs prior to disabling the option.
The Allow Comments option will provide a Comments section along the bottom of your page. This section is usable only by authorized Collaborators and Owners of your site. Visitors who have been specifically invited to view the site as Visitors will see the comments, but not be able to leave any, and anonymous visitors will not see the Comments section.
Placing a check in the box next to Show this Page in the Sidebar will add the page to the Navigation gadget in your site's sidebar. The value that is entered as your Page Title is what will be displayed.
The Page URL is the actual URL for your page. Unlike your site name (URL), the page URL can be changed and reused through this option. See the related article on how to Reuse a Page Name (URL).