1. How do I save? In the upper left corner, click on the Microsoft Office Button. It opens a command menu.

2. Can I still use the shortcuts that I did with the previous version of Office? Yes, however, a menu no longer appears to remind you of those shortcuts. A menu is located in the HELP file under Keyboard Shortcuts for Microsoft Office Word. You can also find a menu of keyboard shortcuts at the following sites:
In addition, the 2007 Office has new shortcuts, called keytips. The keytips are visible after pressing the alt key.

3. Are files created in the 2007 version compatible with previous versions? Yes, but some items may not appear or may not work in an earlier version. Users of the older versions have an opportunity to download a compatibility pack upon opening a document from Office 2007. If you know that someone does not have the newer version, it is probably best to save as (under the Microsoft Button) as an older version. In the reverse, documents created in older versions can be opened in the 2007 version and run in a Compatibility Mode.

4. I can't find a command in the 2007 version, but I know where it is in the 2003 version. What can I do? Dowload this interactive guide from Microsoft. Simply place your pointer over the 2003 command, and it shows you where to find that command in 2007. http://office.microsoft.com/en-us/word/HA100744321033.aspx