1. Fill in the Google Sheets template at http://timeline.knightlab.com/, including the date, text, and url for the media you wish to include.
2. Publish your spreadsheet. In the File menu, select "Publish to the Web," then copy the URL for the spreadsheet from the browser toolbar.
3. Paste the URL into the "Generate your timeline" box at http://timeline.knightlab.com/, then click Load. Edit the settings if necessary.
4. The site will provide you with a share link, and an iframe embed code. Copy the code and paste it on your web page.
Additional directions, FAQs, and help are available on the Knight Lab website.