To my understanding, the bible is divinely inspired by God? However is this the only book that has been inspired or developed through this method? Are there other books equivalent or near equal to the bible in regards to Christianity?
It's just a matter of what you believe or what you don't believe... The Koran was inspired by God (according to Islam) and it also mentions Christ in there. There also might be other books/literature about any specific topic. But categorizing it as "divinely inspired" will just be based on your belief and trust on people who claims that it is "divinely inspired". I mean how can you tell if a book is really divinely inspired? Is it because the book itself say's it is? Or is it because some people say it is? How do we determine if a book is genuinely divinely inspired? We must first establish a set of rules on how to determine something before we can say it is part of that category.
Prerequisite: Before giving a straight answer, we need to deal with the canonization of the Bible which is a subject of endless debate. Therefore, let us assume that the Bible in this context means the complete Bible including the Apocryphal Books as well.
Are there other books equivalent or nearly equal to the bible in regards to Christianity?
There are some books nearly equivalent to the books in New Testament Canon but not equal.
Epistles of Clement: This epistle was included in many of the oldest surviving copies of NT.
Epistle of Barnabas: Very important epistle written by Barnabas who was a companion of Saint Paul.
The Shepherd of Hermas: Less important but found in many old codices.
Dialogue with Trypho: A good book which defends the early Christian Faith and theology. Trinity concept is well explained here.
Didache: A book which explains the ordinances of the early Christian church. Method of Baptism is well described.
Still there are some authentic books which are of far less importance, written by the Church Fathers, but I don't think they are worth mentioning.
Conclusion: As mentioned, these books are not equivalent to the NT Canons but are very close. There is no need of reading them because they speak the same thing what the Canons are saying. They are useful only to defend the authenticity of the NT Canons and to know the early Christian Faith.
Note: Only the NT Canons are regarded as Divinely Inspired by God. Other books like the ones mentioned here may or may not be inspired by God. Even, how the Book of Revelation was selected instead of The Apocalypse of Peter in the NT Canon is also something which we don't really understand.
The canon has included only those books which are inspired and there are no other books equivalent or near equal.
Why only these are considered inspired?
If God were to authenticate any of the books as His communication and therefore as inspired teachings, He would have to verify it in a manner that could not be duplicated by mere humans. Otherwise people could make up their own messages and simply claim that they came from God. God achieved this by fulfilling of many prophesies recorded in these books over the ages.
The real determination of any books claim for its inspired truth is in its supernatural evidence, including prophecy. God used prophets to speak and write down His Word and God used miracles like fulfilled prophecy to authenticate His messengers. For example, in Genesis 12:7, God promises the land of Israel for Abraham and his descendants. In 1948 Israel was returned back to the Jewish people for the second time in history. This may not seem so astonishing until you realize that no nation in the history of the world has been scattered from its homeland and returned! Israel has done it twice. The book of Daniel predicts with accuracy the coming of the four great kingdoms from Babylon, to Medo-Persia, to Greece, to Rome centuries before some of those kingdoms came on the scene (a time span of over 1,000 years!) with details concerning how they would rule and be broken. This includes the reigns of Alexander the Great and Antiochus Epiphanies.
In the book of Ezekiel 26 we can see in astonishing detail how the city of Tyre was to be destroyed, how it would be torn down, and how its debris would be thrown into the sea. When Alexander the Great marched on that area, he used these rocks, the leftover rubble from the city of Tyre for the land bridge.
There are several prophecies concerning Christ in the books of Old Testament and it would take more than a few screens worth of space to list them all. Further, Jesus would have had no control over many of them such as His birthplace or time and type of birth. Second, the odds of one man accidentally fulfilling even a very few of these is miniscule.
There are other books (after canonization of Bible) claiming to be inspired but they make clear historical and judgemental errors. Others have no fulfilled prophesies to claim that they are inspired. There are these other books which makes judgments against Christians for believing things that they do not (nor have they ever) believed. For example, there claims that Christians believe the Trinity is the Father, the Mother (Mary). Divinely inspired books need at least be able to accurately report what is being believed by others.
To keep it short and sweet: no by definition.
To elaborate a little bit, the Bible is itself a compilation of individual books written at various points in history at -- according to Christianity -- the direction of the spirit of God (i.e. not just written, but inspired). The compilation of books that are judged to be inspired is known as the Canon. There are a lot of steps and factors that went into deciding what was Canonical and or not (and even a couple differences in Canons used by major divisions within Christianity) but in broad strokes it is pretty well settled.
The simple answer is "no" because if according to Christianity there were any other inspired works that carried the authority of divine inspiration, they would have been part of the Canon. You are asking if Christianity considers anything else to be inspired: the Canon is the set of things we believe to be inspired works on the same level.