The Stewart Calculus website has tutorials, online quizzes, a review of algebra, a collection of 'lies' that your calculator might tell you, a collection of challenge problems and more.

University of Illinois at Urbana Champaign Calculus and Mathematica course
Calculus and Mathematica is a calculus course that is taught with no lectures; all class meetings are in a computer lab where students work on projects.

Wright State Calculus Laboratory Program
Calculus classes at Wright State have a calculus lab component with a number of downloadable Mathematica notebooks.

Calculus Self Tutoring by D.C.M. Burbull and C.T.J. Dodson at the University of Toronto.
A number of Mathematica notebooks designed for self-instruction in Calculus.

Wolfram Mathematica Online Integrator
An interactive integration tool that uses Mathematica to evaluate integrals symbolically.

Calculus by Gilbert Strang is an online calculus textbook.

Also check out Others and General for other resources including online calculus courses, online review material, virtual math communities and on-line question and answer services for students and teachers.