As an archer, I have the option of choosing bodkin or broadhead arrows as my special item. However, I haven't figured out a way to switch to them in game. I can't even find a way to tell what type I am currently using. Are the special arrows automatically equipped?
Yes, the arrow type you are using are the ones you have chosen. There is no way to change them in game except to change your class and repick them. To see which arrows you are fireing off, you can look at the tip. The Bodkins will have very small piercing type (To go through thicker armor), and the broadheads will look more like the normal arrows you are used to seeing (Arrow shaped arrows :p).