Guides is in gray, smart guide is in black. I want guides. What to do?

To learn Photoshop I'm using the Lynda.com course. I'm in the Fundamentals chapter 9, Select and Edit. This is the first chapter to give me trouble.

I have all the appropriate files open and I'm following along. The teacher has us Command A to select the image, Command T and R to transform the image and bring up the rulers. He then drags the guides to aline them in the center. When I move the guides the whole image moves compressing into itself.

I then go to View, Show and look through the drop down menu. Sure enough, Smart Guides are turned on and in black and Guides is in gray, so I can't select.

I've been going nuts trying to bring up the guides and I can't do it.

I've aligned the movie to make sure every setting on the teachers monitor match mine.

How do I turn on guides? Is there an easier way to find the center of an image?

Thanks