To add a publisher to your Favorites, visit any publisher page by going to Browse Publishers, and click on the publisher name (you can also click on the publisher name on any title details page). Then once you're on the publisher page, click "Add to Favorites."
To remove a publisher from your favorites, just click the same button, which now says "In Your Favorites."
Once you've added publishers to your favorites, you will see them listed on your Dashboard under "Favorite Publishers" and you can also see the available titles from your favorite publishers by going to Find Titles, and on the left-hand side, click "Favorite Publishers." Being able to see all of your favorite publishers and their titles all in one place will make it easier for you to find books you're interested in.