The Italian Renaissance spans from the 14th century to the beginning of the 16th century. Most classic paintings and statues that we immediately think of as Renaissance art, however, were completed during the High Renaissance, from the 1490 to 1527. While this movement took place in different areas of Italy, when you think Italian Renaissance, think Florence, Florence, Florence...with a dash of Rome, thanks to Michelangelo.
The leading men (female artists, in this time period, were few and far between—sorry, ladies) during the High Renaissance were everybody's favorite Teenage Mutant Ninja Turtles: Leonardo [da Vinci], Michelangelo, Raphael, and Donatello. These guys set the standard during the High Renaissance for color, proportion, and composition. They would be nothing without a few artists who came before them, though.
Giotto was one of the first artists who added weight and personality to his subjects. An easy way to remember his work is with the quote, “Giotto makes massive Madonnas." Then there was Masaccio, who was an early adapter of linear perspective. He was a brilliant mathematician and a talented artist (there were a bunch of those types of guys during the Renaissance).