In this tutorial we’ll talk about expanding your canvas outside of where your PSD began. By using Canvas Size we can crop without deleting parts of our image (we can do this with the newer Crop tool too,) we can expand our image and add transparency or a color to any or all sides of our image, and we can even automatically trim away any leftover transparent bits of the image. You’re going to enjoy this tutorial!
Advanced Photoshop Course: http://tutvid.com/advanced-photoshop-tutorial-bundle/
How to Retouch Images Course: http://tutvid.com/retouching-photos-photoshop/