Laxmi Ganesha Statue should be kept on the right side of the Goddess Lakshmi and Goddess Saraswati should be placed on the right side of Goddess Lakshmi. Idols of all of these God and Goddess should be in sitting form
The Northern portion of a home is associated with wealth. Hence, ideally, the Lakshmi pooja should be conducted in that location. However, do not keep two idols of the same god in the pooja ghar.