There are two pretty popular ways to crop an image using Photoshop.

The first method involves the use of the Rectangular Marquee tool. Use the marquee to select the portion you want to REMAIN in the image.  Changing the style to “Fixed Ratio” will even out the height and width of the image after the crop. Select Crop from the Image menu in order to complete the crop.

The second method utilizes photoshops designated Crop Tool. This tool allows the user to adjust the borders around the crop, generally making this method the better option for those who may need to be more precise. Once the borders are all in place, hit Enter to complete the crop.