Is there a way to send an email to a group of contacts on gmail?

I’m hoping this question has an easy answer that I’ve somehow missed in my own searches.

I’m just trying to send an email to a group of people at the same time without having to type in each of their names or email addresses. (The “nicknames” feature doesn’t save any time for me, since these are my students, and I have 40–60 new names every quarter. Names written in Chinese characters.)

On hotmail, this was easy. Just type in the name of the group and it send the message to all included in that group. Is there such a function on gmail? Is the “label” function anything besides labeling and storing away?

Please help!