Volume 1. Nekomonogatari: Shiro
From Hanekawa's point of view, Nekomonogatari Shiro starts from the first day of the new semester, Hanekawa meets a giant tiger on the way to her school then her house is burned out. She can't find Araragi, but Senjougahara comes to help her..
Volume 2. Kabukimonogatari
Shinobu and Araragi go back in time to finish his summer homework but they accidentally go back eleven years in the past and end up saving Mayoi Hachikuji, which turn out to be an event that will change the whole world in the future...
Volume 3. Hanamonogatari
This novel happens after everthing has ended (when Araragi and Senjougahara went to university). Kanbaru finds her alone and there's no one she can talk about kaii (abnormalities). Then there's a strange rumor about a Devil-sama who will solve everyone's problems. Kanbaru comes to see the Devil, and the next day she finds her arm has became normal. But is this what she really want?...
Volume 4. Otorimonogatari
Nadeko hallucinates and do everything the snake god on her hand tells her as a redemption for what she's done to snakes. But her actions will lead to an unavoidable fight with Araragi and Shinobu...
Volume 5. Onimonogatari
This novel happens at the same time with Nekomonogatari Shiro
. On the first day of the new semester, Araragi meets Hachikuji, Yotsugi, then suddenly a mysterious black thing appears and attack them. They escaped, hide, and hear Shinobu tells about her past, since she has encountered that black thing once, and it's inescapable, unless...
Volume 6. Koimonogatari
From Kaiki Deshuu's point of view; On a holiday, he receives a strange request from Senjougahara, told him to deceive a God. After some investigation, he thinks that job is easy and accept it. Everything went so well, but the end is not what he expected...
(Source: Bakemonogatari Wikia)