She said she has been keeping good records since she was first elected to Parliament in 2002.
The book, which she has yet to name, will have her take on where she sees the country going and the opportunities she thinks should be embraced.
"But there will also be quite a large opportunity to go through some of the big events that I've been a party to, and part of, so I can give another angle.
"There are things when you are in Government sometimes you just can't say and you just have to keep your mouth shut.
"Now, I'm not in that position anymore."
One area of focus for the book will be "what happened to me in 2014".
That was the year the Dirty Politics book was published, exposing links between Collins and controversial former Whale Oil blogger Cameron Slater.
She was forced to resign as Justice Minister shortly before the 2014 election but was later cleared of wrongdoing in the Chisholm report.
Collins said: "I can now actually tell what was going on behind the scenes and what was happening – for anyone who is interested in politics they might find it deeply thrilling at times."
She said over the years she has been approached by a number of publishers who were keen for her to write a book, but she had never felt that the time was right.
"I think the time is right now," she said.
"I have so much information that I might as well just pull it together."
Asked when the book will be finished, she said: "when it's finished".