When writing a letter of recommendation to a book president, you should pay attention to the following points:

1. Briefly introduce yourself: At the beginning of the letter, briefly introduce your name, education, professional field and work experience. This will help the president of the book get to know you and judge whether you have relevant background and ability.

2. Emphasize your professional knowledge and skills: describe your professional knowledge, skills and research direction in detail in your letter, especially your experience related to book publishing. For example, you can mention your ability in editing, proofreading and typesetting, as well as your ability to understand market trends and readers' needs.

3. State your interest and motivation in the book club: explain to the book president why you are interested in the book club and choose to recommend yourself. You can mention your appreciation and recognition of the publishing direction, book quality and company culture of the publishing house, and explain why you think you are a suitable candidate for the publishing house.

4. Summarize your contributions and ideas: In the main part of the letter, list some ideas that you think you can contribute to and improve the book club. For example, we can put forward strategies to expand publishing channels and increase book sales, or put forward suggestions to adjust publishing catalogues according to market demand.

5. Express your enthusiasm and sincerity: At the end of the letter, reiterate your enthusiasm for joining the book club and thank the chairman for his time and consideration. And remind the president of your contact information, so as to further communicate and interview the possibility.

Finally, make sure that the overall structure of your cover letter is clear, the language is standardized, the words are accurate, and avoid any spelling and grammar mistakes. At the same time, according to the specific background and recruitment requirements of the book club, personalized modifications and supplements will be made. Good luck!