For those unfamiliar with the term, cropping is the process of removing the unwanted parts of a picture.
1) Open the image you want to crop.
2) Select the scalpel tool from the toolbox.
3) When you drag the cursor over your image, it should now look something like this:
4) Select roughly the upper left corner of the portion you want to crop. Don’t worry about being exact since you can make fine adjustments later.
5) While holding the left mouse button, drag the cursor to the lower right of the portion you want to crop. As you do this the portion of the photo that will be removed is slightly greyed out while the portion that will remain is shown full color.
6) If necessary, you can make fine adjustments to the portion that will be cropped by pressing the up and down arrows for the Origin X, Origin Y, Width, and Height entries.
7) When you are satisfied with the selection, press the Crop button.
8) Save the image.