What type of angel was the Morning Star? I've read in various places that Lucifer was 'Chief of the Seraphim,' 'Cherubim that covers,' and 'Archangel of the Crown'.  All accounts say he was God's greatest angelic creation, but what kind: Seraph, Cherub, or Archangel?

I'm a novelist and I am currently doing research. If you don't mind, I would like to know what the general consensus or most common views are across Christianity.
You have hit upon a very popular misconception which many have turned into a fable. The only place in the Bible which names "Lucifer" is in Isaiah 14:12.


  " How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!"  (KJV)


This verse is contained within a section that is discussing the king of Babylon.  We can know this by looking at the entire chapter, and we find in vs. 4 that the text actually says "king of Babylon" and also calls him "the oppressor".  

Then, in vs. 16 it identifies him as "the man"...


  "They that see thee shall narrowly look upon thee, and consider thee, saying, Is this the man that made the earth to tremble, that did shake kingdoms;"  


The entire section is one of prophetic judgment which was pronounced against the king of Babylon for his pride and conceit and claim to be like the most High.  

Adam Clarke's commentary is most helpful here, and regarding "the parable" of vs. 4 includes:


  "The Septuagint in this place render the word by θρηνος, a lamentation. They plainly consider the speech here introduced as a piece of poetry, and of that species of poetry which we call the elegiac; either from the subject, it being a poem on the fall and death of the king of Babylon, or from the form of the composition, which is of the longer sort of Hebrew verse, in which the Lamentations of Jeremiah, called by the Septuagint Θρηνοι, are written."


And regarding vs. 12 he has:


  "O Lucifer, son of the morning - The Versions in general agree in this translation, and render הילל heilel as signifying Lucifer, Φωσφωρος, the morning star, whether Jupiter or Venus; as these are both bringers of the morning light, or morning stars, annually in their turn. And although the context speaks explicitly concerning Nebuchadnezzar, yet this has been, I know not why, applied to the chief of the fallen angels, who is most incongruously denominated Lucifer, (the bringer of light!) an epithet as common to him as those of Satan and Devil. That the Holy Spirit by his prophets should call this arch-enemy of God and man the light-bringer, would be strange indeed. But the truth is, the text speaks nothing at all concerning Satan nor his fall, nor the occasion of that fall, which many divines have with great confidence deduced from this text. O how necessary it is to understand the literal meaning of Scripture, that preposterous comments may be prevented! Besides, I doubt much whether our translation be correct. הילל heilel, which we translate Lucifer, comes from ילל yalal, yell, howl, or shriek, and should be translated, "Howl, son of the morning;" and so the Syriac has understood it; and for this meaning Michaelis contends: see his reasons in Parkhurst, under הלל halal ."  


And on vs. 13:


  "I will ascend into heaven - I will get the empire of the whole world. I will exalt my throne above the stars of God - above the Israelites, who are here termed the stars of God. So the Targum of Jonathan, and R. D. Kimchi. This chapter speaks not of the ambition and fall of Satan, but of the pride, arrogance, and fall of Nebuchadnezzar."  Source: here


Clarke's entire discussion of this chapter would be helpful to you.  

Young's Literal Translation of Isa. 14:12 does not use "Lucifer" at all.


  " How hast thou fallen from the heavens, O shining one, son of the dawn! Thou hast been cut down to earth, O weakener of nations." (YLT)


Prophetic language of the Bible has some common metaphors which can be identified through scripture.  "Heaven" or "Heavens" is used for the kingdoms and realms of authority of kings as they have a higher authority over the people of the land.  As God has authority over all men, and as He raises up and brings down the rulers / kings over men, then the king's rule is a "heaven" / authority appointed by God.

"Casting down to earth" was being removed from power.  The earth was a metaphor for the realm of the common people who had no authority above one another.

The "stars of God" were those stars of heaven that are identified through metaphorical statements as the children of Israel / Jacob and his father Abraham.

Gen. 26:4, remembering the oath to Abraham,


  "And I will make thy seed to multiply as the stars of heaven,..." 


Joseph's dream in Gen. 37:9,


  "... and, behold, the sun and the moon and the eleven stars made obeisance to me."


is defined in verse 10:


  "...What is this dream that thou hast dreamed? Shall I and thy mother and thy brethren indeed come to bow down ourselves to thee to the earth?"


The eleven stars were Joseph's brothers.  So all of the children of Jacob / Israel were referred to in prophesy / poetical language as "the stars of heaven."

We need a Prophetic Language Class 101 so that these metaphors can be more readily recognized.

I do not know that the particular king spoken of in Isa. c. 14 was Nebuchadnezzar as verses 19 &amp; 20 says he slaughtered his people, and destroyed his land.  As Nebuchadnezzar returned to his sanity (Dan. 4:22-37), and seemed to have repented of his pride, this king in Isa. c. 14 might very well have been Nebuchadnezzar's grandson Belshazzar.  Belshazzar was the last king of ancient Babylon mentioned in Dan. c. 5.

This may not be of help to you in your novel.  Contrary to what most people believe, "Lucifer" is actually a mistranslation, and is not a reference to any fallen angel, nor to Satan.

Unless otherwise noted, all scriptural references are from the KJV.  All bold emphasis is mine.