Texas Instruments
Texas Instruments: Parametric and Polar Graphing
Here's an activity to use to teach students how to use the TI-86 graphing calculator to graph functions in parametric or polar modes. Calculator keystroke instructions and calculator screenprints are given in this student activity.
George Mason University
Handmade Manipulative Instructions
At this personal site, you will find pages of math manipulatives and different types of graphing paper to print out and use in your classroom.