Here are some links which I find useful.
Pure Mathematics UWaterloo
Fields Institute
Simons Center for Geometry and Physics
Perimeter Institute
arXiv:Differential Geometry
arXiv:Symplectic Geometry
Mathscinet
Thematic Program in Geometric Analysis - Fields
Institute
Simons Collaboration on Special Holonomy in Geometry, Analysis,
and Physics
Spiro Karigiannis' collection of important links in the
study of G2 manifolds