A few weeks ago the New Yorker ran an article on the so-called gospel of Judas, an early gnostic document, and about Judas himself.
James Grant has a helpful interview with Dan Wallace about the article, Judas, and the document associated with the betrayer.
I appreciate primers like this, which can help us remember key truths, such as three features of gnosticism (matter as evil, rejection of the OT, and salvation through secret knowledge) and four tests of canonicity (orthodoxy, antiquity, apostolicity, and catholicity).