Understanding editing a Drupal page

When logged in, most pages can be edited from the page itself. Depending on the administration theme, there is usually an edit button associated with each piece of content that makes up the defined web page.  The edit button is usually above the page title along with tabs such as View, Outline, Revisions and Track. Sometimes the tabs are located on the far left margin of your site that appears only on a mouse role over.  In either case, the edit function will be located in the same place for all content that is editable with in the site.

Understand that editing a “page” of your website can also be confusing for more complex designs that use Views or Panels.  A view is a page that is created using different pieces of content.  Think of it like the way a newspaper is laid out.  Each story may come from another page and it is put together in a Drupal View or Panel.  Editing these pieces of content is easy when you go directly to the original page of content.  Editing content directly in the view is not possible.   Therefore, when you are on a piece of content and see the edit tab, you can edit the piece of content and it will be updated in the view.  If you can not see an edit tab on a page, the page may be built in a view and you will need to find that piece of content to edit it. 
Another way to edit content is to use the menu bar at the top of a logged in session.  There is a standard black band with menu items such as Content Management, Site Building, and others depending on your accounts permissions.  To View all of the content in your site, select [roll over] Content Management  and then click on Content. Your entire site of content will be listed by content type.  Content Types vary depending on your site but you should see types of content such as Page, Blog Entry, FAQ, or Panel.  You can select Edit under the Operations column.  You can sort this list of content by Status [published or unpublished] Type or Category.  The most common sort to use is by type.  If you are looking for a page you can sort by type to only see page type content.  Then scroll the list of content to find what you are looking for and edit it.  Also see How to Edit a Drupal Page.