To begin battle, simply click on the round gold plate type object near to where the girls are standing. They will automatically move to a new battle position after winning the current or previous battle.
When you're in battle, click and drag your healer (Flora or Stella) onto another winx to continuously heal them. For the other winx club girls, simply click and drag them onto an enemy to begin attacking. To move around, just click where you would like to move.