If you create a shortcut, then right click on it and select the 'shortcut' tab above, you'll see a field that says 'run'. It will usually default to 'normal window', just click on the drop down togle and select 'maximized'.
Bear in mind it has to be a shortcut and not the icon from where the program is launched.
Or, as Steve mentioned, you can, from a normal screen, use the arrow at the bottom left corner of the screen and drag it to full size, then when you open it next time, it will be that same size.