Paquita Boston's website offers two books to help you understand English spelling, both are paper books, one is in e-book form.
Please bother about spelling. It is the very first thing kids learn at school. This influences their attitude to learning for the rest of their lives. A teacher’s mission in life is to encourage curiosity and teach logical thinking. Every curious kid deserves logical answers to questions about spelling.
"Why doesn't bother rhyme with brother?" is a reasonable question.
A teacher can answer this using my big book "Reading with Rules". No prior knowledge needed.
You'll get an over-all look at spelling in my book "The Inside Story on English Spelling".
Be a hero to your children and your students. Answer their questions. They deserve it.