Heh, you are right. That's the iOS 4.3 PDF, even though the link is clearly labeled for iOS 5. I'm sure Apple will catch their mistake with the PDF version soon. In the mean time:
If you go into your Safari bookmarks, at the very bottom of the root directory you will find a link to some help pages that may have what you want.
Or you can download and read the iPad User User Guide for iOS 5 in the iBooks app. It is free. I checked, it is the right manual.