It depends what you want to do with it. NTC is a temperature variable resistor. If you have wanted to control the processor temperature with a fun, you could assemble an analog circuit powered by pi supply.
In case you want to measure a temperature you must have to connect an AD converter to the pi and NTC must be connected to the ADC. But be careful, NTC has a logaritmic characteristic, ADs has linear; so you need linearisation circuitry with resistors. NTC-s are most sensible to temperature sensors, so do not be afraid from the first difficulties.
on a Raspberry B+ with whezzy, two Zero with Jessie Light