When wanting to print a booklet, the pages from the Indesign document have to be sorted into an order that makes it possible to print double-sided and fold the resulting pages into a booklet. This tutorial explains how this is done.
Each page of your document needs to also be on its own page in Indesign. Make sure you have a number of pages that can be DEVIDED BY FOUR.
If you use a non-standard paper size it is handy to still create the pages on a standard Ax size because of printing double-sided. Be mindful that the width you need for printing is twice the width of your page - so if you have pages in A5 landscape, you need to print on A3 paper in order to fit two pages next to each other, as seen in the picture above.
Go to File >Print Booklet.
Most likely you want to select 2-up Saddle Stitch which results in a page order as seen above.
Go to Print Settings. Under General, select Print Blank Pages if you have empty pages in your document that you want to be included in the printing.
Select Setup. It is handy to print the document to pdf first, so set a PDF printer. Check the paper size: this is TWICE THE SIZE (width) of one page, so assuming you have portrait select A3 for A4, A4 for A5 etc.
Check the Orientation: this is the orientation of two pages of your document next to each other. Hence, for two portrait this is LANDSCAPE.In the Options section select Scale to fit.
You have now completed the print setup. Click OK.
In order to check how the booklet will be printed, go to Preview.
The last and first page should be seen next to each other. There should not be a message that says that blank pages have been inserted. This is the case if the page number is not dividable by four or print blank pages has not been enabled.
You can now print the booklet. (Click Print.) For a PDF it will ask you where you want to save it.
Select the correct orientation: LANDSCAPE. Select the correct paper size; remember that it was double the document page size (A3 for A4 etc).
Under Detailed Settings>Edit select Duplex>short edge. Click OK.
The booklet will be printed.