An updating of the list published in the Mathematica Journal, Volume 5, Issue 3.
http://smc.vnet.net/mathsite.html
Users of the software package Mathematica may share tips and advice at the comp.soft-sys.math.mathematica discussion list.
http://mathforum.org/epigone/comp.soft-sys.math.mathematica/
Mathematica notebooks created by Gary Stoudt for teaching and illustrating concepts in the course "Advanced Mathematics for Applications" at Indiana University of Pennsylvania. Most have some discovery learning built in. Free to download.
http://www.ma.iup.edu/projects/CalcDEMma/advmath.html
A multidisciplinary journal that publishes articles about the use of Mathematica in higher education at both the undergraduate and graduate level.
http://link.springer.de/link/service/journals/00545/
An online companion for differential equations contains demo notebooks, packages, and links.
http://www.math.armstrong.edu/faculty/hollis/mmade
mathStatica solves the algebraic / symbolic problems that are of primary interest in mathematical statistics. It does so by building upon the symbolic computational power of Mathematica.
http://www.mathStatica.com
A Mathematica-based calculus course.
http://www-cm.math.uiuc.edu/
Moderated email group for Mathematica Users. A free service of Steven M. Christensen and Associates, Inc.
http://smc.vnet.net/MathGroup.html