Enthusiasm is high during the start of the school year so capitalize on it by coming up with great activities to engage your students.  Here are a few ideas

Katie at msmathmadness has come up with this great idea using dice to break the ice with a new group of students. 

Be sure to check out her blog here for more great first day ideas

This table seating jigsaw is a great idea from the curriculum corner.  They have plenty of other great ideas here also.

Becky at Dots n Spots has a great Guess who task to help find out about everybody in the room.  Take a look at it here.