The Page Layout tab in Excel 2007, 2010, and 2013 has a scale to fit group. Change the Width to equal 1 page and the Height to equal 1 page from the drop down lists.
After you change it to 1 page for the width and the height you will notice the scale changes from 100% to a lower amount if it necessary.
I think that anything over 70% should work. Lower values will obliviously make the font smaller when printed.