The first and maybe most obvious is to click on enhance>convert to black and white. Yeah, that's all you have to do! Once the dialog box opens though, you can tweak to your heart's desire. In Photoshop Elements there are different styles you can choose from: portrait, scenic landscape, urban/snapshots, or the one I chose here is called newspaper. Then you can tweak further by adjusting the slider bars to adjust the intensity of red, green or blue, or adjust the contrast.
Another way to convert to black and white is to create a black and white gradiant map adjustment layer. I like to use this method when I want to let some of the color peek through. So after I create the layer I turn down it's opacity. On this one I used about 50% opacity.
A third way (and another of my favorites) is to simply run an action. I have gotten all of my actions for free, mostly from the Pioneer Woman or the Coffeeshop Blog.
This one is the Pioneer Woman's Heartland action.
And this one is Coffeeshop Blogs Classic B&W with the "high key" layer turned on.
Look at how the different methods can have such different outcomes. All black and white, but none of them are the same!
Which is your favorite? And please, feel free to share how you like to convert your black and white photos!