First and foremost, the entry should be welcoming.
It should be inviting and friendly and not institutional-looking or forbidding. We know that community involvement in schools is a key factor in their success and so the community needs to feel that the school belongs to them.
This welcoming aspect has to be balanced by the need to secure the entry and separate it publicly accessible spaces from the student areas.
To learn more, order The Language of School Design: Design Patterns for 21st Century Schools (Nair, Fielding)