By Douglas Eyman
There are two kinds of commenting tools available in Microsoft Word: in-text commenting (using a different font color for each commentator), and a system that allows you to provide pop-up annotations that are indicated by highlighting that appears on a word or phrase. I recommend using the latter method because it is less intrusive. If you have sound capabilities on your computer, you can also add audio commentary to a draft, but be aware that the file size expands very rapidly when using this feature.
You can also use simple highlighting as a kind of shorthand to draw attention to surface error. Word's highlighting tool allows you to accent text in a range of colors, creating a system in which different colors indicate various types of content, grammar, and spelling errors. Dickinson College's Instructional Technology: E-Grading site offers a good overview of how to use highlighting in Word.
Resources for Working with Microsoft Word