Photoshop CS3 Tutorial
How to Align Shape Objects in Photoshop
Aligning shapes manually can be a tedious process. It is a real time saver to select multiple shapes and let Photoshop do the work.
Open a new blank document in Photoshop (File > New). Set the size to 500 pixels by 500 pixels and the resolution to 72 ppi.
Click the Rectangle tool and set the options to Shape Layer.
Use the Rectangle tool to draw three rectangles in the workspace.
With one layer selected, Cmd (PC-Ctrl) click the other two. All three shape layers should be selected.
Choose Layer > Align + Vertical Centers.