I think he just wants a left-side margin or some padding. Text-indent is for first-line indents only.
That said, if you want to keep the width of the text the same and just knock it over a little bit (
including moving over the background image), then you would add the following to your #menu selector:
If you want to move the text over, but
not the background image, you'd use this instead:
Of course, adjust the width of your menu box as necessary.
