To publish a post in the Publisher section, click on Create New Post. You will then be asked to choose which platform and page you would like to publish to, by clicking on Select page or profile:

You are also able to select multiple profiles at once so your post will be published across platforms. You can publish on Facebook, Instagram, Twitter, Google+ or Pinterest:

After you have selected your page, you will see a text box where you can write your post and/or add any media. You can click through the icons below to schedule the post or use PrimeTime to see recommended publishing times.

If you would like to add additional profiles of which you are an admin, click on Add Profile at the top of the page:

You will then be prompted to connect your profiles: