Geometric Topology

Crystallographic Topology
The Topology of Crystallographic Groups and Simple Crystal Structures
http://www.ornl.gov/sci/ortep/topology.html

Geometric Topology
Numerous links in the Geometry Junkyard.
http://www.ics.uci.edu/~eppstein/junkyard/topo.html

3-Manifolds
Links to low-dimensional topology resources.
http://www.math.unl.edu/~mbrittenham2/ldt/3mfld.html

Manifolds and Cell Complexes
Section 57 in Dave Rusin's Mathematical Atlas.
http://www.math.niu.edu/~rusin/known-math/index/57-XX.html

The Optiverse and Other Sphere Eversions
Article by John M. Sullivan on sphere eversions, with numerous illustrations.
http://www.math.uiuc.edu/~jms/Papers/isama/

xxx Math Front: GT Geometric Topology
Preprints in geometric topology in the Arxiv.
http://front.math.ucdavis.edu/math.GT