The cover letter is the first point of contact you will have with a potential employer, so make sure you invest time and effort into making it resonate with them in an impressive way.
Individualize your letter to each preschool
You would be surprized how many prospective teachers use a standard letter for everywhere; and it really shows.
Undertake your research of the preschool and mention something early in your letter about why that thing has led you to apply. For example: “I know the Wuthering Heights Preschool heavily emphasizes community involvement in its program; this fits perfectly with my own philosophy of teaching, a copy of which I enclose with my application.”
Including a statement like this demonstrates that not only are you considerate of what’s important to the preschool, but because you’ve taken the time to individualize your application you are obviously the kind of person that commits energy to important tasks.
Also in your cover letter you should include a mini-biography of yourself; that is, where you come from, what education and experience you have, why you love teaching and what you can bring to the centre to which you’re applying – as before, make sure this is individualized, at least to an extent.
The ideal length for a cover letter is about 150-250 words. You don’t need to go crazy with it, just keep it succinct and relevant to the job description; if they are seeking someone with specific skills and you lack them, this is also your opportunity to demonstrate your willingness to learn on the job.
The mere fact that you aren’t a 100% fit in terms of your expertise is not a deal-breaker – but you are better off if you confront these shortcomings in your cover letter, while emphasizing all the positive things you can bring to the job (not least of all your energy and desire to improve yourself on the job).