Different people wrote different ones. Exactly who wrote what depends on who you ask. In general, each book has a "traditional" author and at least one other candidate (whose name we may not know).
One reason for this is that some scholars refuse to believe in, for example, prophecy. So a book that contains a section foretelling the future "can't" have be written by the guy whose name is on it, it "must" have been written by someone after the events described in it had already happened.
Wikipedia has a pretty good article on this; I'm going to refer you there (look in the Related Links) instead of retyping it all here.
Joshua and Nehemiah both wrote the books in the Bible that bear their names. It is not known if they wrote other books in the Bible.
John wwrote the last four books in the bible.
The apostle Paul wrote Titus. This is the twelfth of the thirteen books by Paul to appear in the Bible.
God directly wrote no books but He inspired all of the writers of the Bible.
Tradition has Moses writing the first five books of the Bible. See related link:
No jesus never wrote any book in the bible.
Several people. That is why there are the different books in the bible.
ezra and nehemiah
In the bible it might be in the back of the bible or in the books paul wrote when he was writing to the churchs from prison.
People who wrote the bible books were many prophets. And all prophets were called for gods work.
ThenBook of Galatians which is one of 66 books in the Bible was written by Paul
In most cases they are the individuals that wrote the books or whose doings were recorded there.