I have two questions. 1. How do you save a backup copy of a document?
2. How do you recover the text from a damaged document?

1) Use File>Save As to save the document in a different folder or a different name (i.e. MyDoc_BU.doc). Or you can copy the saved file using Windows Explorer or My Computer.

2) If a document has been damaged and there is a autosaved version, you will be presenterd the opportunity to use the autosaved version.

Some fun reading:
http://support.microsoft.com/Default.aspx?kbid=107686