Use this Student Information Page at the beginning of the year. I usually pass it out at Open House or on the first day of school. This page requests student's name, date of birth, age, address, parents' email addresses, allergies, medications, parents' phone numbers, and three things the parent(s) would like the teacher to know about the child.
I have found this form to be very helpful year after year. I usually take these forms on field trips in case there is an emergency.