EasyJetRyanAir fly to Milan. Lots of other companies aswell but I have flown with the two above before to Milan many times.Then you can get a coach to the city for a small amount or so (you can buy coach tickets on the flight sometimes but they are generally a bump).I always just get a return ticket for the coach when I arrive(lots of different coaches outside the aiport ) and it is usually is 10euros for a returns give or take.Takes about 1hour from any of the Milan Airports to Milan Main Train Station. From they're it's easy to get to most places as there is bus,trams, subway and overland trains .nearby. Taxi's are quite exspensive in this area for obvious reasons so it may be beneficial to walk out a couple of blocks if you are on a tight budget.