Click on 'Insert,' again at the top of MS Word. When the menu appears, let your mouse arrow hover over 'Picture.' Here you'll have several options. You can create your letterhead on the fly using some of those options. However, for our purposes we'll opt to choose 'From File,' since we already have a ready graphic. Click on the option, 'From File,' and a dialogue box opens. Locate your graphic and then click on it and then click the 'Insert' button. Your graphic will then appear inside the dotted box.
You can align your logo by clicking any of the alignment buttons at the menu bar. Press the 'Enter' key on your keyboard and you can type in your business address or a slogan. You can format the text just as you would when you're creating a MS Word document. You can choose the font, font size, color, align the text and even add graphic lines.