Reddit mentions of The Book of Margery Kempe (Penguin Classics)

I was racking my brain for good suggestions for secondary sources (having studied the period for four years, I should have some, right?) when it dawned on me that... I don't have (m)any, because we read primary texts in most of my courses. That being the case, I would most heartily recommend:

• The Canterbury Tales by Geoffrey Chaucer: Smart and funny stories that will make you think and can be read little by little. Along with that is Boccaccio's Decameron: similar in many respects, but I didn't like it as much! Also, um... I've never read all of Dante's Divine Comedy but that's obviously a classic.
  
• The Lais of Marie de France: These will give you a good idea of 'chivalry' in the High Middle Ages; there are 12 lais total, if I recall correctly, all relatively short. See also: Chrétien de Troyes' Arthurian romances; I'd recommend getting a verse translation.
  
• The letters of Abelard and Heloise: This is one of those rare circumstances in which you can really see the voice of a medieval woman. I find their romance rather heartbreaking and fantastic. The letters & writings themselves can sometimes get bogged down in theology and philosophy, but underlying that are two very real, desperate people who had some real nasty shit go down.
  
• Thomas Aquinas: Baller philosopher shutting bitches down with reason. I can see how this might not be your cup of tea, but if you're interested in theology or political philosophy, check him out.
  
• The Book of Margery Kempe: She is hilarious. Eccentric, late medieval English saint.
  
• Plus, if you're interested, there are tons of hagiographies and chronicles to be read, but I find most of those rather dull.
  
  As for modern nonfiction books, I've found it most helpful to find something specific that you want to learn about and look into that. Read about politics in late medieval England, or a biography of Louis IX, or a survey of monastic life--that will get you further than reading a broad history that is necessarily reductionist. If you're truly starting from scratch, I'm sure others can recommend good background books to help you get off your feet, but I find primary sources are the best way to really grasp the 'feel' of a time period.