Cover letter to the resume: how to write it correctly
The basic information that the cover letter should be loaded with is your advantage over others in the context of the proposed vacancy. Indicate that they worked in this (or, at worst, in a similar) sphere.
If you can offer your employer a customer base or vendor base - please indicate. Most often, a good base outweighs any experience.
It is not necessary to describe in detail in the letter all your experience of working with the school, for this there is a resume.
Leaving contact details in the letter is meaningless, do not overload it with unnecessary information. However, it would not hurt to sign up with the presence of the indispensable “Regards. ".
Do not forget the polite form of the letter. At least say hello before starting it.