You can not turn into a werewolf. It is impossible, scientifically and magically. You can not alter your human DNA, or at least can not alter it without dieing. Also, the pure amount of energy you would need to simultaneously alter your structure, bones, skin, and pretty much everything else to match a wolfs is astronomical, and impossible to achieve even if such a thing is possible.
If you are truly interested in magic I suggest you stay away from the 'Fantasy' section of the spells, as they are just that, fantasy, and look toward the 'Newbie Central' section and read the multitudes of informative articles we have on this site.