What should my humidity level be and how do I know what it is?
The rule of thumb is to maintain your humidity levels between 30-50 %, depending on the temperature outside. Humidity levels indoors are typically lower in the winter months and higher in the summer months.
Buy a Hygrometer! A Hygrometer measures the relative humidity (RH) in your home, and can be purchased for a relatively low cost ($10-$60 depending on the type of device) at any hardware, building supply, home electronics store (anywhere that would sell a thermometer for your home). These devices are relatively small and can easily be moved from room to room.