I created a graphic in Illustrator, and there is a lot of white space around the graphic itself, but it is all within the artboard. When I got to export my piece as a JPEG, Illustrator does whatever it wants with the white space; cuts it off, adds more??
By default, Illustrator will only export the exact borders of the "artwork" on the artboard, be it smaller or bigger than the artboard.
In order to use your artboard borders when exporting, make sure to select Use Artboards in the Export dialog.
Additionally, you can use File → Save for Web (Alt+Shift+Ctrl+S) instead, there you can also choose to use the artboard.