Depends on how in depth you want to get. Moore's clinical anatomy is a good mix of anatomy with some patho, but it's written for med students so it's pretty advanced. Saladin has a decent book, and my old professor writes a good book for undergrads (Martini, Tallitsch, and Timmons). If you really are interested in it that much, just head to your local library, pick up a textbook, and read the sections that interest you. Don't worry about reading cover to cover, as you'll get plenty of details later on.
At this point in your education the most important things are to explore your interest and figure out how you learn. The actual material typically won't help in the long run, but if you can figure out how to learn the material effectively it will make your academic career that much easier.
I'm a high school senior and really interested in the body and disease (clinically or not).
