Bow enhancements

What does it mean when my bow says +14% (while enchanted )
How do I enchant it?

Thanks

it means while you have an enchantment spell on you. Rangers don't have any enchantments themselves, so it'd be a spell from your secondary or that someone else cast on you (i.e. a monk's enchantment).

You can notice enchantments by the small yellow upward arrow in the right hand corner of their icon.

Cool! Thanks for the help.