Although you can copy and paste from Word documents, Excel spreadsheets etc. you should be aware that doing this can also import a whole load of extra unnecessary code along with it, which can slow down your downloading time and interfere with non-visual browsers (ie screen readers).
Ideally you should copy and paste using the 'Paste from Word' or 'Paste as Plain Text' options. Usually if I have set up your JCE, it will be set so you have to paste as plain text.
If you don't have JCE, I can install and set it up for you.