Reddit reviews The Books of Enoch: The Angels, The Watchers and The Nephilim: (With Extensive Commentary on the Three Books of Enoch, the Fallen Angels, the Calendar of Enoch, and Daniel's Prophecy)

Hope this helps!

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I got this version a few years ago. It has all three books of Enoch and some other books not included in the Bible with commentary. It’s an interesting read. Its been a few years since I’ve read it, but I recall the author of the commentary showing that, whether we believe the book (First book of Enoch), many people in the Bible do, as they quote it on a few occasions. https://www.amazon.com/Books-Enoch-Watchers-Extensive-Commentary/dp/1936533073/ref=mp_s_a_1_3?ie=UTF8&qid=1549575404&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=book+of+enoch&dpPl=1&dpID=51nJmpZ1PRL&ref=plSrch

There really is very little in official Christian writings about angels. You can read about the nephilim which were supposed to be the offspring of angels and human females during the antideluvian period. They are kind of mentioned in passing in the bible I think 1 Enoch has a bit more info, you can find a book on that here which should help you out.

It's my understanding that much of the Christian idea of angels comes from Zoroastrianism so you might consider looking into that tradition as well.