Groups in Moodle are a really useful tool. You can use them to send announcements to selected students or release certain materials to particular groups or to enable more sophisticated group work. However, they can be a bit of a pain to set up.
In Moodle 3.0 you can let you students decide which groups they wish to be in. First you have to create your (empty) groups and grouping structures, if you aren’t sure how to do this, have a look at our #1minuteCPD posts on groups.
Next, just follow my demonstration below: