Creating a double-sided A5 booklet in Word is a simple task. Microsoft recommends users to set up the format of the booklet before inputting text, images and other content into it. You can take the reverse course as well but you might have to fix the alignment.
Click "Page Setup" on the top "File" menu. Click the "Margins" tab.
Select the option "Book fold" from the "Multiple Pages" drop-down list.
Specify the inside and outside margins in the "Inside" and "Outside" sections.
Select the number of pages of the booklet from the "Sheets per booklet" drop-down list.
Click the "Paper" tab and specify "A5" as the size of the document in the "Paper size" list.
Click the "OK" button to close the "Page Setup" window.
Insert content in the booklet. Press "Ctrl" and "S" to save the booklet.