Traveling to Italy for the first time....please help?

During the Spring Break of 2012 im going on a trip to a few places in Italy.....Milan, Venice,Ravenna,Florence,Cinque Terre,and Rome. This is my first time going to Italy. I dont know the exact date, but I should be leaving probabvly somewhere between late March to early/mid April. So first of all what is the weather like during this time-what should i bring with me? What other additional information can be useful, in general, about these places or the people there,for souvineers is it very expensive there for is it reasonable?,etc. ANY information will be very helpful. If you have been to Italy, please answer my question :) Thanks!