Layout Algorithms

Graph or network "layout" refers to how a network is visualized. To put it mildly, it is a big deal.
Nice diagrams in this software wiki (yFiles Developers Guide

Isabel F. Cruz and Roberto Tamassia Graph Drawing Tutorial
JFLAP Some nice pictures of alternatives.
BoĊĦtjan Pajntar OVERVIEW OF ALGORITHMS FOR GRAPH DRAWING Short description of major types
Somewhat technical description at Mathematica
SCRIBD Document