To view a book:

• Click the title of the book or the cover image.
• On the next screen, click the Start Reading Now button or select a chapter from the Table of Contents. If you don't see the Table of Contents initially, scroll past the book description.  
• Once opened, in a bar running across the top of the screen, there is an option to browse to specific chapters or move to the next section or chapter.
• To the right of the book reader, there are options to search within the book, add it to a personal playlist, change the font size and background color and other options, or share the book on social media or email. 
• To read all pages in a chapter, simply scroll down. O'Reilly's ebook reader features an "infinite scroll" rather than individual pages that need to be clicked through. 

The video player in O'Reilly is similar to other video players you've likely come across.  Standard options include the ability to scrub forward or backward, change playback speed, enter a full-screen mode, and see closed captions.