Perhaps the hardest part of the first day is saying goodbye; sometimes it is more difficult for the parent than the child. Even if you have an open door policy the rest of the year, saying goodbye outside of the classroom makes the parting quicker, if not more painless. If possible, have some of the fifth or sixth grade students on hand to help escort kindergartners to the room. You cannot assume they know how to walk in a line yet, and having an older "buddy" makes getting into the room and finding their seat and their cubby easier.
Choose a "get acquainted" activity so the children learn each other's names. Name tags are helpful for you, but most kindergartners cannot read yet. They will need to memorize the names of their new classmates. Sit in a circle on the rug for introductions. Have children share their name and something specific about themselves; for example, favorite color, food or animal. Introduce a get-to-know-you game that you will play each day until the children have learned each other's names.
The students will be curious about their new surroundings so take a "tour" of the room. This is an exercise to practice walking in line and not touching things unless they have permission. Most of them will not have mastered these skills. Show them the play area, reading area, work tables, cubbies, and any other areas in the room, explaining what activities take place in each area.
Due to the excitement level the first day, playing with the toys is not a good idea. Many of your students will need to be taught not to put toys in their mouths, throw things, or grab items from others. Introduce "free play" time after they have acclimated themselves to the room and your rules. Instead, spend the first day drawing pictures on pre-dated paper to make a first-day picture for their portfolio, reading them stories about the first day of school, and creating a mission statement for your classroom. Example: I will learn my new friends' names, be nice to others, do what the teacher says, and say please and thank you. Have a snack time, show them where the bathroom is, and stress that they must wash their hands before eating their snack and after going to the bathroom.
Teach them the end of the day routine, putting things away, and getting on their coats. If possible, have their "buddy" from the beginning of the day come back to your room to help with this process. You may want to have invited the parents to come to pick them up 10 minutes early and allow the children to give them a "tour" of the room and show them where their cubby is, where they sit, and introduce them to new friends.