I'm an MVC Itaiian owner with properties both in Europe and US and I live since 14 years in Milan. Having all family 1 month or more in an hotel room even if Marriott one could be tough and somehow expensive. I would suggest you look for a short trem apt. MSee these web sites: http://www.rentxpress.com/milan-apartments/globe.phtml?currlang=EN, http://www.rentclass.com/ or http://www.selectapartments.co.uk/results.asp?city=Milan.
If your are relocating for business maybe your company might pay for a full service relocation company to help you and your family to get established (search for a house, working permit, kids school, etc). I strongly suggest to get in touch with www.professionalrelo.com. Extremelly good.