I wrote a little blog about MS Word in the past. I found other very helpful tips from The Word MVP Site. Some examples:
o You can repeat most commands and actions by pressing F4.
o You can use Ctrl+Shift+C to copy formatting and Ctrl+Shift+V to paste it. Having copied formatting, you can use Ctrl+Shift+V as often as you like – even across multiple documents – without having to copy again until you close Word.
o To return to your last edit point, press Shift+F5
o Press Ctrl+Spacebar to remove character formatting. Press Ctrl+Q to remove paragraph formatting.
o Word outline can be pasted straight into PowerPoint; and this is a very quick way to prepare the guts of a presentation.
o Advanced find-replace