How to reverse the mouse scroll so that moving a wheel up will make the page go up, and a mouse wheel down makes the page go down.
System Prefs -> Mouse. Toggle 'Scroll direction:natural'.
By default on Mavericks if you use a mouse that has a scroll wheel (like the Razer), scrolling down (towards you) will make the content on the screen move up.
To make it so that scrolling down will make the page go down, you just have to unclick the scroll direction.
To get there, go to system preferences
Then select mouse
Then in your mouse menu preferences uncheck the box for "natural" scroll direction