A Dictionary of Angels: Including the Fallen Angels by Gustov Davidson and Gustav Davidson (1994, Paperback, Reissue)

This is a great book, seriously written & wonderfully illustrated, but don't read if you're expecting to learn about how your late Great Aunt Matilda is going to come back to watch over your little dog Fluffy. That's a modern belief engendered from 19th century spiritualism & not any previously existing Christian, Jewish or Islamic tradition.
No, this thick volumes contains in-depth references based on thousands of years of scholarly study.
The common consensus amongst many theologians was, in fact, that angels are sexless & shapeless immortal energy beings who can take human form like, if you don't mind a rather crass modern pop culture analogy, some of the more highly advanced aliens on the sci-fi series "Star Trek" (no blasphemy meant but that really is the best example I can give to a contemporary audience, &, if you think about it, such religious thought was probably an influence on their creation...especially considering that there is, I kid you not, an extremely highly placed archangel named METATRON!).
That's not to say that there aren't echoes of primitive paganism that, like in the present day versions of Christmas & Easter, give an extra bit of mythology-tinged colour to Christianity.
Take, for example, the "Cherubim" which are not, in fact, cute little flying babies but in their most primal form are great winged beasts with human faces who are literal Monsters of God who act as heaven's hitmen.
This book names EVERYBODY in the Heavenly Host, who they are & what they do.
For all the literature out there on demonology (& there is a LOT), it's good to have something that gives you a scorecard for the good guys for a change.
Give this book a try. It may not get you into Heaven, but if you do, at least you'll be able to recognize the staff when you get there.

THIS BOOK IS THE MOST COMPLETE ENCYLOPEDIA OF ANGELS AND FALLEN ANGELS I'VE SEEN THIS BOOK REFERENCES WHERE IT DERIVES ALL ITS INFORMATION AND GIVES A IN DEPTH ACCOUNT OF EACH INDIVIDUAL ANGEL. VERY COOL BOOK!!

It's good in that is has many, many angels. The most prominent names are defined the best. It also differentiates between angels and entities that have been mixed up and identified with eachother; particularly the fallen angels. It's a good book for a writer or RPG storyteller.