It is common for staff in schools and colleges to have an express term written into their contract that sets out the required period of notice to be given by their employer. Alternatively the contract may refer to a collective agreement (eg. the burgandy book) that sets out notice terms.
The contract will also state the notice they as the employee are required to give to the employer. If there is no express term then there is still an implied term of reasonable notice. Reasonable notice will depend on the circumstances including length of service, grade and job role, but ultimately can only be decided by a civil court.