Well, the user manual is installed with LabVIEW. It's in the <labviewdir>\manuals directory. There's also a great big online help available from the Help menu. It's also available online at the NI site.
To learn more about LabVIEW you can look over the material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. You can also take the online courses for free.
