Nara lies nearly due south of Kyoto and is an easy daytrip. Both JR and Kintetsu trains run to Nara, but the Kintetsu makes the most sense if you’re not tied to a JR Pass. The Kintetsu station sits just outside Nara Park which contains not only the Todaiji Temple with its enormous Buddha, but also herds of sacred deer.
You can’t buy the tickets for the Kintetsu trains at the machines downstairs in Kyoto Station. Instead, take the escalator up to the second floor (Look out the windowed alcove to your right at the top for a great view of Kyoto Tower.).