Would like to know the best and Cheapest way to Rome?

Im hoping to visit Rome in May and I would like anyone to give me any advice on which airport to fly to and also train details.Im travelling from England and would like to fly from either Manchester,Leeds,East Mids or Doncaster.The flights to Rome are very expensive and not very often.I have been told its best to fly to Milan and then catch the train to Rome is this true?Im only going for a couple of days,can anyone shed any light on this?cheers