I visited hoping to find a procedure to scan some pages in landscape orientation. I found some handy tips but not landscape.
I found a solution using XSane (below). There can always be other solutions, there usually are on a Linux system.
After scanning a page, XSane usually presents an A4 page in portrait mode. You can change this:
[Edit image]
button[Save multipage file]
to generate a PDF or other file output.The result will have the rotated pages appearing as landscape.