If I could only teach you one thing in this photography basics series, it would be to set your camera in aperture priority for the next six months. When you want full depth-of-field, choose a high f-stop (aperture). When you want shallow depth of field, choose a lower f-stop. Your pictures will DRAMATICALLY improve when you learn to control the depth-of-field.
Potty training in 3 days! This Mom trained each of her kids this way & it worked every time.