Get a digital hygrometer ... forget the analogs, unless you want to have one for "show"
There are a number of good choices for a humidifier and all work well ... Oshkosh is a good one, for example but if it were me (and at my house it is), I'd skip buying any of them and spend the money on cigars ... I make my own humidifiers and they work great ... I suggest Rickamavens idea of using a travel soap dish with a chunk of that green florist foam cut to fit ... be sure it's the wet foam and not the dry, which will not work at all ... drill holes in the lid of the soap dish and VOILA ... a first class high capacity humidifier ... cheap too. Look at the pics board where you can even find a picture of one Rick put in a plastic sweater box that has a cigar box bottom in it ... doesn't look fancy, but it sure will work ...