You can turn the pages over by grabbing the corner edge of each page and dragging it over like you would with a real book. You can also use the big blue tabs at the side of each page to quickly move forward and backwards through this catalogue section.
You can zoom in to each page by using the magnifying glass icons on the bottom menu bar. The magnify icon with a + symbol zooms the page in. The magnify icon with a - symbol zooms the page out. The Ruler 1:1 icon zooms the page back to its normal size.
You can jump straight to a particular page by entering a page number directly into the page entry box on the bottom menu bar and pressing the 'go' button.