Anticipating a stay in Italy, and nervous about speaking the language? Not surprising; a lot of Italians do not speak english. Nevertheless, Italians are very forgiving when it comes to their language. Some appreciate the effort and will wait patiently while you sound out what you need.
The general suggestion is to purchase a travel dictionary that includes basic phrases. There are also pocket electric dictionaries available; literally pocket size, they are more portable than a book, and include up to five different languages.
Having stated that, you'll find many shop keepers, hotel clerks, and restaurant staff speak some english. It varies by city; in larger cities, you'll find more english-speakers than in rural areas.
Below are a few articles that may help you before beginning to learn Italian:
Phonetically speaking: using phonics, it's possible to speak simple Italian.