Grading

Is anyone else having the difficulties I am with grading. Tonight was open house and as of yet I have virtually no grades for my physics kids. While I have done quite a few labs and discussions to this point, I really don't have anything to grade them on. Maybe participation in the talks? I am giving the first graphing deployment activity tomorrow, but even that I question taking for a grade. What have you guys taken for grades yet? How are you going to handle discussions with respect to grading?