This batch file was updated on May 9, 2016.

Reading order:
Volume 1-13
Volume SS1
Volume 14-16
Volume SS2
Volume 17-22
New Testament series

If you are someone who has seen both seasons of the Index anime and are wondering where to pick up the novels, I would urge you start at the very beginning.
However, if you really don't want to do that, my suggestion would be to read the epilogue of Volume 6, the epilogue of Volume 13, and Chapter 3 of SS1.
After that, start at Volume 14 and go from there.


For side stories:
Volume SP and Kanzaki SS should be read at some point before starting New Testament. I would recommend reading them after either volume 18 or 22.
The Shoukuhou Misaki Figurine SS contains plot spoilers from NT8.
The Circumstances Leading to a Certain Magical Heavy Zashiki Warashi’s Simple Killer Queen's Marriage parody story contains plot spoilers from NT10.

As for the other side stories and parody stories, they have less of a need to be read at a particular time.
Therefore, I will list what volume the story was on when the side/parody story was released.


I do not recommend reading these after the listed volumes. It is just there to give you context to when they were released.

Side stories:
Railgun SS - Last part was released after volume 18.
Toaru Jihanki no Fanfare - Released after volume 19.
Love Letter SS - Released after volume 22.
Railgun SS2 - Last part was released after NT2.
Railgun SS: A Superfluous Story - Released after NT3. It is meant to be an epilogue story to the Railgun PSP game.
Road to Endymion - Released after NT6.
Necessarius SS - Last part was released after NT9.
New Testament SS - Released after NT10.
Toaru Majutsu no Virtual-On - Released after NT15.
A Certain Midsummer Return to the Starting Point - Released after NT16.
Using Final Bosses to Determine a Sociological Threat - Bundled with NT17.
NT18 Bonus Story - Bundled with NT18.

Parody stories:
A Certain Prophecy Index - Released after volume 5.
A Certain Academy Index - Released after volume 6.
A Certain March Gift Exchange - Released after volume 11.
A Certain March 201st Volume - Released after volume 11.
I Don't Want this First Story - Released after volume 14.
A Certain Collaboration - Released after NT7.
Kamijou-san, Two Idiots,... - Released after NT16.