Vertical master page spreads
There is however ? thanks to some Page tool magic ?a much simpler technique we can use to create vertical master page and document spreads in InDesign CS5.
Unfortunately this trick does not work for facing pages documents, but it works quite beautifully for non-facing pages documents.
To begin start by creating a new document (File > New > Document) and clear the Facing Pages check box.
The new document will contain one master page: A-Master. Display the Pages Panel (Window > Pages) and right-click the A-Master.
Choose Master Options for "A-Master"... from the contextual menu that appears.
Change the Number of Pages from 1 to 2 and click OK. The Pages panel will now display A-Master as a page spread. Double click A-Master to select it.
You've now created a vertical master page spread. Just note that the Pages panel does not display spreads as vertical. However, when you insert the page spread, you are generating vertical spreads in the document.
It's now time to add some vertical spreads to your document. In the Pages panel, select A-Master and drag and drop it next to page 1 in the document.
Next, delete Page 1 by selecting it in the Pages panel and clicking the Trash icon at the bottom of the panel.
To add more vertical page spreads, either repeat the drag and drop master page action, or with the current document page spread selected choose Duplicate Spread from the Pages panel menu.
Your document will end up with vertical page spreads.