Saving a word document as read-only in MS Word 2010 is very similar to how you would do it in Word 2007. You can also apply a password to restrict users from modifying the document.

1) Click on File.
2) Go to Save As.
3) Click on Tools then General Options…
4) You can enter a password in for opening the document and/or modify if you wish.
5) Check the box next to Read-Only recommended.
6) Click OK