Travel from Malpensa airport

Just wanted to say thanks for any help in advance..well we've got out hotel booked its Naviglio Grande in milan via rossini....is it best to catch a bus there from Malpensa airport and if so which one ? Can someone please give me the best bus service or cheapest way to travel from the airport to the hotel....will i be able to buy our tickets on the saturday or wait till the sunday....we can't wait to go..I'm a Portsmouth fan and my son loves Milan..we saw ACMilan at fratton park..great game..will it be a full stadium.... oh we travel out sat morning...