They are really easy plants. Grows like a weedy and very open tomato plant. The thing is they will not set fruit unless you have at least two as they need cross pollination. But For me to get lots of fruit I always planted at least 3.
They really taste great in salsa and years ago I used to make a salsa verde from tomatillos with cilantro and onions and I forget what. It was a long time ago and I since lost the receipe.