Because you're going to be folding this Easter card in half, and then in half again, you want to type your personalized Easter message in the opposite corner from where your image is. This is where the gridlines feature in Word 2007 comes in handy.
First, turn on your Show/Hide so that you can see your paragraph marks. (The Show/Hide button is on the Home tab and looks lie a backwards "P".)
Then go to the View tab and check the box next to Gridlines. You should now see vertical and horizontal lines across your holiday greeting card. Don't worry, these lines do not print out. We are just using them to help us align where our personalized greeting will go.
Now, press the Enter key several times so that you are just past the middle of the document.

click to enlarge