Go to the Users tab on the Management page. Find the user that you want to assign specific pages to. On the right side of the page, click on the Actions dropdown, and then click Page Assignments. This option will only show up for users who belong to a school organization AND who have projects in the current season.
On the next page, you can select the list of pages that you want this user to be able to see. If the user has multiple projects they can see, they will have a dropdown to select between the different yearbook projects.
If they only have a single project, they will just see the name of the project in the top left corner of the tab. This is similar to what most school advisors will see.
It defaults to all pages. You can unselect the pages that you don't want to be visible, or click Select All in the top right to start with none selected and add back the options that you want selected.
When you are done, scroll down to the bottom of the screen and click Save. That user will only be able to see the selected pages now!