I explain Edmodo to my students the following way: it's basically educational Facebook. It looks very similar to Facebook, but the teacher controls what's on it and what's not. The teacher can post assignments, message, alerts/reminders, or polls.
What you, as a teacher, would need to do is create a teacher account. From there you create groups, such as "English 2 Period 3" or simply "Period 3." Once you create a group (which you usually sort by class), then you'll get a group code. This is what you give to your students so they can join your group.
The students will first have to create an account. Make sure the information they use is valid. A helpful hint, I told my students to use FirstnameMiddleinitialLastname. That way, it was easy for them to remember. In any case, I have a tech card (a note card) where the students put their user names and passwords. I keep it, so if they need to look at it, I've got the information for them.
Once the students have their accounts they must "Join" a group. That's when you give them the code. These are the basic first steps to setting up Edmodo!
