What software should I use for writing a book?
The book contains a lot of graphs, arrows, and other graphical stuff.
I need a software which is easy to use and does not require any special skills. I need a software for the layout. For the end result, PDF would be best.
Here sounds LaTeX like the tool to go! LaTeX is good for formatting and writing books. It automates stuff like text and image alignment and it compiles into pdf.
It is a language you have to learn, but it is easy. With it's big community on stackexchange you can find an answer to almost every question. You can simply search LaTeX and you will find the right page. There are some commands you need to know, but with a cheatsheet which you will find on Google too, it's no big deal. Just as a hint. Compile the file after a change twice to apply every change you have made.
There are several editors supporting LaTeX. I would recommend:
If you truly want to get into publishing, which will be more complex than MS Word, but will give belter, more professional results, then you ought to look into the excellent, and free Scribus.
It is not as full featured as Adobe, but has the most important features (read a comparison), and see an overview of features here.
their list of “Made with Scribus” includes books on Open Source software, so it should be fine for you.
Adobe Indesign is pretty much the de facto industry standard for book layout when text and graphics need to be incorporated together. It's used for everything from RPG books to textbooks, and it's $19.99 US per month (about $240 US every year).
Of course, there are a lot of alternatives, both commercial and non-commercial. I personally like Scribus, but there are other possibilities here: http://alternativeto.net/software/adobe-indesign/
If you are familiar with Microsoft Word, you can use that. If you don’t have the budget, then the excellent, free Libre Office Writer is equivalent and compatible.
Writer exports directly to PDF. For Word, Windows 10 has a print to PDF option and there are plenty of free PDF printer driers which you could use for other versions of windows.
