PDF is a file format which allows the exchange of complex formatted documents among many users, independent of the details of hardware platform or word processor software on any local computer.  It is an outgrowth of software originally developed to make computer generated documents directly readable by commercial printing equipment.  Download and installation of the FREE Adobe Acrobat Reader software now makes it possible for just about any web connected computer to read .pdf files on their local screen, and to produce printable versions including graphic information..

    Since PDF was originally designed pretty much to generate a "book", one commonly locates information in .pdf files by the same techniques one would use with a book -- look up a page number in the Index or in the Table of Contents, or else just browse from page to page.  Modern versions of Acrobat are even more sophisticated, so that .pdf documents with internal hyperlinks are now possible.

    Here are some handy tricks with acrobat reader that might be helpful in navigating through .pdf documents.

    1.  The "Grabbing Hand" -- Acrobat commonly loads with a single page displayed on screen, and with the cursor in the form of an open hand.  Pressing the mouse button will cause the hand to close, allowing the page to be dragged around the screen.

    2.  The top tool bar -- Icons across the top of the screen have reasonably familiar shapes, and are provided with popups to describe their purpose when pointed to with the mouse.  The icon for the currently active cursor mode (probably the hand) will appear to be depressed.  Next to the hand is the magnifying glass cursor, which provides dynamic zoom capability -- just activate that cursor, position the magnifier at the center of the area of interest, and use left click to magnify or right click to reduce.  There are also several buttons farther right on the toolbar to rapidly change the magnification (full sized -- fit screen width -- fit in screen) without changing cursors.
    Near the middle of the bar are some triangle and arrow icons, for moving forward and back through the document -- either page by page, or view by view (this latter more like browser "forward" and "back" operations).

    3.  The bottom bar -- At first glance, seems primarily information readouts.  From left to right are values for the current magnification, the current page number, and the actual dimensions of the printable area (i.e. with margins subtracted).  A closer look shows some familiar looking triangle symbols here.  The one to the right of the magnification value pops up a menu of zoom options.  The ones on either side of the page number display operate just like those on the top bar to move through the document.
    The icon of a printed page also pops a very useful menu -- this allowing one to shift the display from one page at a time to a continuously scrollable view of the entire document.

    4.  The main Scroll Bar -- Acrobat does not do real-time scrolling as one drags the scroll box along the bar.  Instead, it provides a pop-up display showing the target page number that will be centered in the window if the mouse button is released at its current position.  Thus, to find page 16 (for example) simply drag the scroll box in the appropriate direction until the pop-up shows number 16, and then release the mouse button.

     SO -- one basic navigation technique for .pdf files is to search the table of contents in the early pages, or else scroll quickly to the end of the document to locate the index, and look up the appropriate page number for the topic of interest.  Then use this pop-up display on the scroll bar to move quickly to the desired page.

    5. The navigation screen -- Through all of this, you may have been seeing a document that fills the full width of your screen, or you might have the document in a window on the right hand side, with a narrower window open along the left edge -- depending on startup settings in your Acrobat Reader and the file being viewed.  Press the icon just to the LEFT of the %size readout on the bottom bar (the icon that looks like two triangles, back to back, with a vertical line between) to open and close the left-hand window.  This narrow window is the navigation screen.  Note that the document magnification automatically changes to fit exactly the same view of the page into the new document width as the navigation screen is opened and closed.
    There are three tabs at the top of the navigation screen -- bookmarks, thumbnails, and articles.  In a full-featured .pdf document, all three of these tabs may contain useful information.
    The bookmark screen might be blank OR it might contain an abbreviated table of contents, with live hyperlinks to jump directly to the desired section of the document (like the index, for instance).
    The "thumbnail" screen pops up a display of numbered miniature pages.  Scrolling this thumbnail display to the desired page number and then double clicking on that mini-page icon will take you directly to that page in the full sized document on the right hand screen.  The clever improvement in more modern, full-featured .pdf documents, is that the thumbnails will show a miniature image of the actual appearance of each target page.

    SO -- to get around using thumbnails.

• Open the thumbnails screen
• Scroll to the highest page numbers (where you would go to find the index in a book.) and double-click the thumbnail page icon to go there.
• Use the index to look up the page number for the topic you seek.
• Go back to the thumbnail screen -- scroll to the desired page number -- and double click its icon.
• You're there.  Use the zoom, the scroll bars and the grabbing hand to move about and read comfortably.