Many node types, such as news stories, are automatically placed on the site in the section they belong. If you're adding a new "page" type or webform, etc., you need to tell Drupal where it goes on the site.
On the edit page, you'll see a section called "Menu Settings". If it's closed, you can click the name to expand it.
Menu Link Title
This is the text that will appear as the menu item. In general, this should be exactly the same as the title of the page so people aren't confused. It may, however, need to be shortened if you have a long title or if it would be repetitive because of the menu item it falls under. For example, if you have a section called "Board Members" and under that there's a separate page for each year, your page may be titled "Board Members: 2000" but you could simply make the menu item "2000" to keep it simple.
This is the menu item your page falls under. In the above example, "Board Members" would be the parent item for your page. If you are creating a new main menu item, you would select "<Primary Links>" or the name of the menu block you want to add your page to. Please contact me before adding a new main menu item as there may already be a different place for it in your site architecture plan.
This determines where the menu item is shown on the list of menu items. Larger numbers move the menu item down on the list, and smaller and negative numbers move the menu item up on the list. If all menu item weights are equal, the new page will be alphabetical in the list. It's easiest to leave this alone and move menu items around on the menu administration page.
Submenu and Siblingmenu Tree Settings
These options refer to displaying a list of other pages into the content area of the current page rather than your page's menu item. This is useful if you're creating a new section and want other pages in the section listed and linked automatically.