I will present some results on the structure and cohomology of mapping class groups of non-orientable surfaces, work deeply influenced by Fred Cohen. These include (1) the projective plane and Klein bottle Cases, (2) Nielsen realization for non-orientable surfaces, (3) non-existence of sections for the natural map from Diff(N_g) to Mod(N_g), and (4) results on the Farrell cohomology of these mapping class groups. This is joint with M. Maldonado, C. Hidber, N. Colin and R. Jiménez.