How to measure EC, pH, 10k thermistor, DO, and Ion-selective probes
Thermistor:  To measure the temperature of a thermistor, first determine your temperature range that you are interested in, and convert that to delta R of your thermistor.

With this information it will be possible to determine the optimum circuit for detecting that range of temperatures.  You may find that a thermocouple may be better suited to your application for larger temperature ranges, at the expense of the circuit and software complexity, involved with instrumentation amplifiers and software to perform cold junction compensation.