Fira (also called Thera or Thira) is the main town of Santorini island, located on the top of a cliff of a caldera. The museum, the cable car, and the few bars and clubs, its central location makes it a good base to use as there are buses from many other parts of the island.
Every day during the summer, Fira is a bustling metropolis as cruise ships from all over the Mediterranean and Aegean seas descend. As a result, prices in Fira (and Santorini generally) tend to be a little higher than other Greek Islands. When there are several ships in port, the lines at the cable cars connecting the Old Port, where the cruise ship tenders dock, with the town of Fira on top of the cliff may become very long.
Information on how to get into Santorini can be found
From Santorini airport: by taxi, or shared-ride shuttle
From the old port, where cruise-ship passengers arrive by cable car, donkey or by foot up the cliff face.
Fron the new port (Athinios), where all the ferries arrive by taxi (expensive) or by local bus (2€, can be crowded), or by shuttle bus value for money
The main bus station of Santorini is in Fira, where you can catch a bus going almost anywhere on the island, usually hourly (every 30 minutes on 6/29/2009). The schedules are posted here daily. Up the stairs behind the bus station and across a parking lot to the west is the main taxi stand.