Ms Sue or Damon, as Writeacher is on vacation, I really hope you can check my today's post. I still have a few other sentences.It is extremely urgent!!!

1) To be honest, I had never heard of Derek Landy, but I found out, to my surprise, that he is a well-known Irish contemporary writer who was educated at your school.
2) I read that his first book, Skulduggery Pleasant, won the Red House Children’s Book Award whereas his second, Playing With Fire, won an Irish Book Award for Children’s Book of the Year. Both books have been translated into Italian and published by Rizzoli.
Do you think I should ask my students to read one of them in English?
3) By the way, I will talk about your proposal on summer courses at our teacher-parent meeting of next Tuesday.
4) My mum is seriously ill at the moment and she needs to do radiotherapy on her vocal cords every day. If she gets better, I may decide to come to your school myself together with my son and some of my students. Now I can't make any decision for the future.
5) I need to receive the list of the participating students along with a short letter of presentation of your school on behalf of (from) your headmaster before our next week's meetings.

Good.

The last sentence, "on behalf of . . ." is fine.

Sure, I can help check your post and answer your question. Let's go through each sentence:

1) To check this sentence, you can first make sure that the grammar and punctuation are correct. Then, you can check if the information about Derek Landy is accurate. You can search online for information about Derek Landy to confirm if he is a well-known Irish contemporary writer who was educated at the mentioned school.

2) This sentence seems fine grammatically. As for whether you should ask your students to read one of Derek Landy's books in English, it depends on the reading level and interests of your students. You can consider their English proficiency and if they would be interested in the genre of the books. You can also check reviews and summaries of the books to see if they align with the goals of your English curriculum.

3) This sentence is grammatically correct. You mentioned that you will talk about a proposal on summer courses at a teacher-parent meeting. It's a good idea to make sure you are prepared to discuss the details of the proposal and any relevant information that the parents might need to know.

4) This sentence is understandable and grammatically correct. It is important to prioritize your family and your mother's health during this time. Making any decisions for the future, such as coming to the school with your son and students, can be put on hold until your mother's condition improves.

5) This sentence is grammatically correct. You mentioned that you need to receive a list of participating students and a letter of presentation from the headmaster of the school before the upcoming meeting. It would be helpful to clarify the details and deadline for receiving these documents to ensure they are provided to you on time.

I hope this helps!