Reddit reviews Using OpenMP: Portable Shared Memory Parallel Programming (Scientific and Engineering Computation)

Your best bet for learning yourself is to get a book. The biggest issue is their isn't really a generalized book. They are mostly specialized for exactly what you want to do. For example Michael Quinn's "Parallel Programming in C with MPI and OpenMP" is great if you want to wriate a parallel program in C with MPI and OpenMP. You would probably do pretty well getting Using OpenMP and going from there. It should have plenty of examples in C++ to get you started on th right track.