Photoshop Tutorials : Lesson # 6: Adjusting the image

Cropping the image

1. Select the cropping tool (see right) from the marquee tool submenu; 
2. Position the pointer on the image, hold down the mouse button  and drag over the image area;
3. Release the button and press the Enter/Return key.
4. Save the document.

Adjusting the image size

1. Choose Image Size from the Image menu;

2. Change the figures in the Height and Width boxes.

The Image Size box contains two other options:

Constrain proportions: constrains the height-width ratio so that as one value is entered into either the Height or Width box, the remaining box is updated to retain the original proportions;

Resample image: if the box is unchecked, this automatically adjusts the resolution (dpi) to match the new width and height measurements so that the file size remains the same. Larger width and height measurements mean lower resolution and vice versa.

Save the document when you are happy with your settings.