I usually start the intro to circletime by doing storytime while they are at the table eating snack - a small dish with dry cereal works really well for this. Make sure it is a narrow enough top that they need to reach in and get one at a time to take longer and it helps them to concentrate. Then when the story is done I try to do something related to the story. If it works we continue and if not circle time ends with the story. I sneak in the lessons here and there during play so they do "circletime" they just don't know it. I don't do a theme of the week or anything like that but take the lead from them, the seasons, etc. For instance I would see them playing with the firetruck and then get a book about firetrucks and a dalmation dog counting activity. Then go and ask them if they wanted to do the story with me. If the answer is no I either walk away or sit down near them and read the story anyways and generally they will stop and come and interact with me. I don't worrry about having them come and sit in circle and do what we would think of as a usual circletime till they are closer to 2 1/2 as in the year before they will go to school.