With the Internet being so central to everyone's computing experience these days, it's more and more rare to get things like CDs with software on them or printed manuals. That's especially true with Apple products. When you open the box that the iPad comes in, one thing you won't find is a full manual (though there is some limited documentation). The links below will point you to the more complete manuals for the iPad.
Apple called the first iPad both "magical" and "revolutionary." History will judge that, of course, but even magical products sometimes need a manual. The link here will give you the iPad manual in PDF.
With iOS 4.2 coming to the iPad, a tremendous number of useful new features have come to the iPad. This manual will help you understand what those features are and how to use them (PDF).