Create a new assignment (or page, or discussion, or calendar event… or anything that lets you create a description in the so-called “Rich Content Editor”.
The menu will look like this:
You will need to pick which LibGuide you want with the dropdown menus:
Once you have made your choices, click the “Embed Content” button. The LibGuide will show up as a large gray placeholder in your description:
Once you save your page, you will see the final, embedded LibGuide in your page: