Given the many people making weather stations, or using humidity and such sensors, it may be nice to see how some of these things can also be measured or aided by old school mechanical devices as well as sensors.
A nice article is measuring rainfall:
Another nice articles are the one about Dew, the one about Humidity
(For this one Wikipedia is far more informative, but quite complex.), and about Temperature.
From my reads, the MetOffice has fantastic information about everything related to the weather, I'm pretty much addicted to it as much as to Wikipedia. Enjoy!
A long time ago I was training as a Merchant Marine deck officer and had to take MET101: Meteorology for Mariners. We spent a lot of time on the roof of the engineering building spinning sling psychrometers around our heads to measure dew point and temperature. Those things hurt when they hit you...