turtleSpaces has a large set of shape primitives: 2D shapes that are drawn flat relative to the turtle, and 3D shapes that are built around it. These printable guides show each shape next to the command that makes it and the parameters it takes, so you can find the right one at a glance. Keep one open beside the IDE, or print them out for the classroom wall.
For the full details of any command, see the Reference.
The 3D shape primitives. PDF, 978 KB.
The 2D shape primitives. PDF, 240 KB.