I could give you some pointers on where and how to get started, but there’s already some existing over here 
http://discourse.stonehearth.net/t/howdy-yall-i-need-some-help/18165?u=drotten
But I could also extend to what ACEXHUNT said, and point your attention over to Radiants own sample mod. You could study it and see how to mod in a craftable object.
And of course, if there’s something that you’re stuck on, or if you’ve got a question, feel free to come here and ask it. Good luck!