Can a person view certain material so that he can learn to better please his wife? Also, to better understand female physiology?This is only done leshem shamayim.
Physiological material can be studied, in the form of diagrams. But pictures and other erotic material may not be seen and studied. Even with the best intentions in the world, this will certainly lead to hirhurim. In general, as long as one has the basic knowledge, pleasing one’s wife is a matter of experience. Also, ask her to tell you what pleases her, and improvise accordingly.