Dante: De vulgari eloquentia (Cambridge Medieval Classics) (ISBN 0521400643)

Book Description:
De vulgari eloquentia, written by Dante in the early years of the fourteenth century, is the only known work of medieval literary theory to have been produced by a practising poet, and the first to assert the intrinsic superiority of living, vernacular languages over Latin. Steven Botterill here offers the only Latin-English parallel-text edition of an important early work by the author of the Divine Comedy, and the only English translation with thorough and up-to-date notes and introductory material.

Readable:
Did some grad school penance with this one, and enjoyed it, both the introduction and the translation. Not qualified to judge the translation as such, but found it very readable. The whole thing was just very accessible without the edition seeming to apologize for itself or anything like that.