Excel: Ctrl+Page Up to switch to another worksheet.
Word: Double-click on a word to select it.
Word: Triple-click inside a paragraph to select the whole paragraph.
Word: Hold down the Ctrl key and click within a sentence to select the whole sentence. Word often gets confused if the sentence contains a courtesy title such as Mr. or Mrs. (the period is the culprit). In that case, hold down the Ctrl key as you move the mouse past the abbreviation.
Windows: Shift+Delete erases the selected item immediately without moving it to the Recycle Bin.