You just attach the Microsoft Word document on to your post. If an error message pops up, then it means that you either have an outdated version or a brand new version. The only Word documents that can be attached here are for Microsoft Word 97-03.
I use Microsoft Office Word 2007, so I faced this dilema a few weeks ago. If you have a new version of Word, you must save it as a Word 97-03 document (also known as Compatibility Mode). If you want an example of that, look at what I did for this thread: http://pokebeach.com/forums/showthread.php?tid=24484&page=1
I hope this helps.