Click Insert and then either Header or Footer. Dozens of built in layouts appear, click a simple one like Blank.
Double click Type text.
If the picture is stored on your computer, select Pictures and select your picture. If you image is online, select Online Pictures and choose an option. Look for smaller images, such as one you might put on a business card or envelope.
Note: Once you insert the picture, the ribbon automatically changes to Pictures Tools in case you have to edit or resize the picture. To resize, select the image then drag the small boxes on corner of the image.
When you are finished, click Close Header and Footer.
If you only want the logo on one page, see Delete a header or footer from a single page.