Stanford Large Network Dataset Collection (SNAP)
The University of Florida Sparse Matrix Collection (UFS)
Twitter graph (2009)
NetworkX (Python)
JUNG (Java)
Stanford Large Network Analysis (SNAP system) (C++, Jure Leskovec)
MATLAB BGL (Matlab, David Gleich)
Mathematica, Graph and Network Modeling (Mathematica)
David Aldous (Berkeley)
Easly-Kleinberg (Cornell)
Dan Spielman (Yale)
Rick Durrett's book
Networks, Crowds, and Markets: Reasoning About a Highly Connected World
Remco Van Der Hofstad's notes
Alan Frieze's notes (handwritten)