I've read Confucius, Mencius, and Xunzi, and am starting the Great Learning. Generally one would skip to ZhuXi after that, but I would assume a lot would happen in between. The Qin dynasty wasn't very long lasting, so how about from the Han dynasty to the Song Dynasty?
Between the Han and Tang Dynasties Confucianism was probably at an all time low in ancient China with the popularisation of Buddhism, Religious Daoism and Neo-Daoism so as for development of Confucianism nothing too important happened.
During the Tang Dyasnty Han Yu did greatly revive the Confucian teachings but he didn't bring much new to the table being set solely on the revival what he though were the "true" Chinese teachings as opposed to the Babarian Buddhism.
Then of course moves on to Zu Xi, Cheng Yi of the Song Dynasty then Wang Yang Ming, etc.