Step 1: Materials
Regular exercise book,
A working brain.
First, get a regular size exercise book. But, the bigger the better. Some types of paper wouldn't work, so it's better not to use counter books.
Step 4: Folding...
Step 6: Ready the cannons and...
Step 7: SHOOT!
Just added this step in case someone stumbled onto this without knowing how to use it. Just use your fingers as a slingshot. This can be really painful, so be careful!
EDIT: I made this instructable a few years ago as a ( still pretty immature ) 14 year old, so forgive me for the terrible pics and confusing language XD