Kalidas is probably the greatest poet of the sanskrit and his works (books) are as follows -
Plays
There are three plays, the earliest of which is probably the Malavikaagnimitra, followed by Vikramorvashiiya and the last is AbhigyaanaShaakuntala (the most popular one)
Poems
Kalidaaa wrote two long epic poems, the Kumarasambhava and the Raghuvamsha, there are two lyric poems also, the Meghaduta and the Ritusamhara.