Hi everybody. Let $G/P$ be a complex projective homogeneous variety with $G$ a simple Lie group and $P$ a parabolic subgroup. I believe that it is possible to - (1) describe ${\rm Pic}(G/P)$ - (2) characterize the ample line bundles and - (3) express the canonical class of $G/P$ in terms of the nodes corresponding to P in the Dynkin diagram of $G$. Are they some canonical (or a least some good) references where this is explained? This is certainly "well-known by the experts" but I'm not one of them... Thanks to those who will answer.