This tutorial will help you to create a basic 3D extrude effect in Adobe Illustrator CS3.
Create a new document. Choose the star tool and create a star.
Then navigate to the main menu and go to Effect > 3D > Extrude and Bevel.
Select the following settings:
Click OK and this 3D star is what you get.
To see other sides of the object rotate it using the Rotate Tool.
Double click on the Stroke colour in the Tool bar to change the colour of the sides.
It is simple. You can create more 3D stars and design it as below.