A restaurant and a bar are two very different things in Italy. A bar will almost always be a better value. Not only that, but there are different etiquette standards for each.

Bars in Italy are quite different from bars in America. You are required to pay before you order. This is where it becomes important to pick-up some of the language. Pointing and saying "I'll take one of those" does not really fly, especially since the pay-station is usually on the other side of the bar.

You could take a seat and wait for a server, but keep in mind that it usually costs extra to sit at a table. This could be your best bet as a tourist though, so don't rule it out. Just make sure that you know what you want because these places rarely have portable paper menus.

In a restaurant, you must follow proper table etiquette. Italians teach their children from young ages to eat properly. It's similar to American table etiquette, just remember fork in the left hand and knife in the right. Cut your food one piece at a time.