I'm wondering if there is some free software in which I could quite easily compose a book with a lot of images, something like textbooks for children for learning foreign languages (an example: https://thumbs.img-sprzedajemy.pl/1000x901c/33/3f/6b/english-file-beginner-students-book-and-workbook-527649125.jpg ) or board game manuals. I tried doing it in MS Word and I found it terrible (aligning, putting images and text with correct spaces...). I saw recommendations of LaTeX and Scrivener here: Good tools for writing (game) manuals and sourcebooks . But I think it's easier to create such a book in Word than in LaTeX; Scrivener is not free. What do people who do it on daily basis use?
People who do it every day for a job pay for good software.Even as a volunteer for a charity, I paid for good DTP software. It took me about twenty-five hours to create each publication. I paid thirty pounds for professional software (it was nearly twenty years ago) and bought a graphics tablet. The two saved me hours and hours of effort.
Yes, you can create books using Word (which, by the way, costs) but you have to fiddle for long periods of time to get a reasonable result. (I have also run across formatting problems that can't be solved using forums and support -- things that take time in themselves.) If my time is worth say £30 per hour and I save three hours creating a publication using paid-for software, the maths soon becomes clear.
Whether you pay for InDesign is another question. I will be putting to my management that Adobe Cloud is not worth the money and we should buy an alternative. However, I have possibly invested somewhere between ten and twenty hours in learning InDesign. If I rate myselft at twenty pounds an hour (I haven't calculate my hourly rate for my present job), that means I will be throwing away at least £200. You have to factor in learning time and learning resources.
Finally, consider Scribus as a free alternative to paid-for products.