Two of the most important collections of ballads are Reliques of Ancient English Poetry, collected by the eighteenth-century cleric Thomas Percy, and the late Victorian collection by Francis James Child called The English and Scottish Popular Ballads. Child's collection contains 305 ballads and many variants, and many ballads are still known by their "Child number."
Sometimes "border ballad" is used to refer to those ballads that originated from the area around the border between England and Scotland.
Note: This guide is still in the early stages of development.
Three question marks mean I have to write more on the subject. Bear with me.