These aluminium gearmotor brackets will let you mount Pololu's 25D gearmotors to your contraption. The packet pair comes with M3 screws in order to attach your motors. These brackets were designed to feature some flexibility as they have several mounting holes and slots for M3 and #4 screws.
This tiny dual motor driver from Pololu carries a TI DRV8833 dual H-bridge. Supplyied with a 2.7 - 10.8 V voltage, it can deliver 1.2A (2A peak) to two DC motors. It integrates protections against reverse-voltage, under-voltage, over-current, and over-temperature.
The SparkFun 1643 board is designed for use as a base for the Honeywell HIH-4030 humidity sensor. It delivers an analogue output voltage proportional to the humidity measured by the sensor making it easy to interpret.