A friend showed me a copy of 'Modesty Check' (PDF file) by Carolyn Mahaney and Nicole Whitacre (both of Girl Talk) a while back. I thought it was excellent and wanted to share it with you, especially this quote from John MacArthur:

How does a woman discern the sometimes fine line between proper dress and dressing to be the center of attention? The answer starts in the intent of the heart. A woman should examine her motives and goals for the way she dresses. Is her intent to show the grace and beauty of womanhood? Is it to reveal a humble heart devoted to worshipping God? Or is it to call attention to herself and flaunt her beauty? Or worse, to attempt to lure men sexually? A woman who focuses on worshipping God will consider carefully how she is dressed, because her heart will dictate her wardrobe and appearance.
-- John MacArthur