My wife and I are finally going to Italy this year. The last two weeks of September. Flying round trip to Rome with the intention of heading north to Venice on 1st day of arrival and then working our way south. Areas on our list are Venice, Florence, Cinque Terre, some of Tuscany & Umbria, down to the Abruzzo area (wife has distant relatives in Teramo), down to Naples, Sorrento and then back to Rome to finish.

I am looking for recommendations on booking accommodations. Budget goal is to try and stay under 200 Euro a night (although I know that may be tough in areas). What methods/people have others used successfully?