A .022 wound string is used for the bass string, a .013 is used for the middle string and a .012 is used for the melody strings. A good idea to keep the dulcimer from slipping off of your lap is to use a car chamois cloth. Just rinse out the cloth and let it dry before using it. It will have a good grip. I like the color of a chamois too.
Dulcimers are handmade and very beautiful.
The peg head can have wood or metal tuners. Most dulcimers have 17 frets. Try to learn the frets from the beginning without numbering them. This will help you in the long run. Your dulcimer should have sound holes in the soundbox itself.