To start reading a book, you should:
Click the button on the toolbar in the upper part of the program window or press the key combination Ctrl+O.
If a document has a description, it will appear in a separate window after you open the document. If you do not want to read the document after reading the description, click the Cancel button in the lower part of the window or press Backspace on the keyboard. If you want to start reading, click the OK or press Enter. After that, you can start viewing the book.