Here you go, Glennis
Canning Tomatillos
Home canning of tomatillos is about the same as canning tomatoes. First, husk and wash the tomatillos. Then gently cook them in boiling water until tender (about 10 minutes), drain and pack into hot sterile jars. Fill the jars with the hot cooking water to within 1/2 inch of the rim. Add 1 tsp salt and 2 tbsp lemon juice or 1/2 tsp citric acid (per quart) to each jar. Seal the jars and place in boiling water for at least 30 minutes.
Edit- IT's suggested that you use the hot pack method. They don't float as much and since they shrink a bit in the hot water you can fit more in.