Place your cursor in your Word file exactly where you want the citation to appear. Click the Insert Citations button on the EndNote toolbar in Word and enter a keyword to locate your citation, then click Insert. Your citation will be formatted and a bibliography generated automatically. Each time you add another citation, EndNote will add the new reference to the bibliography. Change the citation format by choosing a style from the Style menu.
You can open up any Word file and insert citations all at once at the end of your writing project, or insert them as you go along. If you save this document, at your next writing session you can continue seamlessly. Just make sure that you are using the SAME EndNote library file each time you open the document.