One of the series of Grothendieck’s works is FGA (see entry EGA for overall description of EGA, FGA and SGA). A summer school in Trieste 2003, has tried to summarize some of the main historical breakthroughs of FGA in modern exposition. The proceedings of that school are an updated version of freely available materials on the ICTP web.
Angelo Vistoli, Grothendieck topologies, fibered categories and descent theory (1–104) MR2223406; math.AG/0412512.
Nitin Nitsure, Construction of Hilbert and Quot schemes (105–137) MR2223407; math/0504590
Barbara Fantechi and Lothar Göttsche, Local properties and Hilbert schemes of points (139–178) MR2223408; (draft pdf)
Luc Illusie, Grothendieck's existence theorem in formal geometry (179–233) MR2223409; (draft version pdf)
Steven L. Kleiman, The Picard scheme (235–321) MR2223410 (draft pdf)
See the conference page for scans of the lecture notes.