Hi, anybody know where to get some good free/cheap plugins and how to install them? I downloaded a couple and they have .h and .nri files and I'm not sure where to put them.

Not trying to be an ass, but seriously read through the 2 manuals. It will take you a couple of evenings and will change the way you think about the software.

Drop the .h files in your ~/nreal/include/startup directory. The UI.h files go in ~/nreal/include/startup/ui. The .nri files go in the ~/nreal/icons directory.