After suffering from a month of dry skin and cracking lips, we bought a humidifier....but soon discovered that mildew loved anything and everything in our house. So what did we do? We purchased one of these to keep an eye on the humidity ion our house, so that we could keep it at a more balanced level.
We bought the Acu-rite Humidity Reader from Walmart, and it's performed splendidly. It has an easy to understand readout, and even gives you a little warning if the humidity is too low.
The only complaint I have is that its a bit slow in reading the percentages sometimes...and at others it jumps wildly around as it tries to figure out the right temperature. Otherwise it's worked very well so far for us, and we don't plan on getting a replacement until this one is compleely broken!