Do you use a humidifier?

Being new to central heating and the climate I now live in I must say I am finding it difficult.

The last few weeks have gotten a little chilly so I have started using the central heating. My sinuses definitely do not like it. I find my sinuses and mouth are quite dry. I bought a humidifier, was this a good idea? I am totally confused since I thought if it was cold and wet the air would be moist in general.

Do you have a humidifier? If so how do you use it? How expensive or cheap was it? Does price make a difference