Altering Objects
Making a Yin-Yang Symbol
As the best way to learn Illustrator is to dive right in and try things, this tutorial will run you through making a yin-yang symbol. As we said before, you can make very complex shapes by combining simple ones, and a yin-yang symbol is no exception.
Step 1: Creating the Objects
A yin-yang symbol is made up of several circlesfive to be exact. To make a circle in Illustrator, select the Ellipse tool and click once where you want the center of the circle to be. The Ellipse dialog box should appear.
If you make the height and width the same value, you'll get a circle. Repeat Step 1 five times, using the following values: 400pts, two 200pts, two 100pts.
Step 2: Cutting Pieces Apart
Once you have your circles, you can focus on making a single, black and white, background circle. One easy way to do this is by cutting your large circle in half and coloring each half (it could also be done with gradients, but doing that will be covered a few lessons later).
To cut your circle in half, choose the Direct Selection tool 
and use it to select the right-most point of the circle.
Once half of the circle is selected, pressing the key once should make that half disappear!
Okay, so now you have half a circle. Using the Selection tool, select the half-circle and copy it using <Ctrl>C (Windows) or <Cmd>C (Mac OS). Then paste a copy of it on the artboard using <Ctrl>V (Windows) or <Cmd>V (Mac OS), just as you would copy and paste in most applications.
Step 3: Putting It All Together
Line the two half-circles up with each other and you will see that now you have two "C"s and not a circle! To fix this, use the Reflect tool to reflect one of them over its vertical axis. Line up the two new pieces, change the colors as needed, and you have a bi-colored circle!
From here, it's all downhill. Just move the circles around and use the Layers palette to stack them the way you want, and you're done!! I made one a little more complex, however:
See if you can make one that looks like this using the Transform tool! Remember, similar concepts can be applied to other complex objects. Analyze the object, look for simple shapes, and work on one section at a time.