Calendars

NU math calendar - U of Chicago math calendar - UIC math calendar
DePaul math calendar - Upcoming dynamics conferences

Math resources

Encyclopedia of dynamical systems
Math Images - Wolfram Demonstrations Project
AMS - MAA - MathSciNet - arXiv

Blogs etc.

Math in the Media - Math in the News
Terry Tao's blog - Geometry and the imagination - Low Dimensional Topology
MathOverflow - Top Math Blogs - nLab Math Blogs
Vi Hart - xkcd

LaTeX resources

TeXample - LaTeX Reference Manual

Teaching resources

Teaching strategies and materials (NU) - Syllabus tutorial (Minn)

Other

The Veritas Forum - St. Olaf College - Huebner column
Alex Ross - Mathematics Magazine articles