To ascertain a basic understanding of your body type:
Measure your bust at the fullest part
Measure your hips at the fullest part (often the groin or upper thighs)
Measure your waist at the narrowest point
I will use a hypothetical woman with 38-inch hips to discuss how your results may affect your body shape.
Women who do not have a very defined waist, ie, neither hip nor bust measurement is more than 8 inches greater than the waist measurement, are rulers. This can also be called the banana. An example might be a woman who has 38-inch hips, a 32-inch waist, and a 37-inch bust. Her hips are nearly the same size as her bust, but her waist is not very defined. If a ruler feels she has a belly she wants to hide, she may prefer to follow guidelines for an apple.
If your waist measurement is bigger than your hips or your bust measurements, you are an apple. An example would be a woman with a 35 inch bust, 39-inch waist, and 38 inch hips.
If your hips are your widest measurement by more than two inches, you are a pear. An example would be a woman with a 35 inch bust, 25 inch waist, and 38 inch hips.
If your bust is your largest measurement by more than two inches, you are an inverted triangle or strawberry. An example would be a woman with a 41 inch bust, 32 inch waist, and 38 inch hips.
If your bust and your hips are roughly the same size (within two inches), and your waist is at least 8-10 inches smaller you are an hourglass. An example is a woman with a 37 inch bust, 27 inch waist, and 38 inch hips.