Preparing your post in Ms Word is a good idea because that gives you a permanent record (on your own harddrive) and gives you access to the spelling and grammar checker . . . however . . . Word saves a lot of code into the file that can mess up the layout in WordPress.
Get rid of this code by pasting it all into the little accessory program called Notepad (comes with Windows). Then cut and paste this text out of Notepad and into WordPress. This strips all the code off for you.