There are different ways you could do it. The most common is to (when one is facing the icon corner) have the Theotokos on the left, Christ on the right, and the icon of St. Nicholas could be under them (or saints flanking them). Some use shelves (I do) and others hang them on the wall. Since you printed them, you could get matching frames for them or whatever.
Here’s what mine currently looks like: (Please Note: This uploaded content is no longer available.)