If you are involved in a more formal conflict (for example harassment or bullying), you need to ensure:
you understand your roles, responsibilities rights and obligations clearl;
all meetings are minuted and all your points are recorded;
you involve your union or staff body representative;
you keep a written record of what happens, and log any evidence, witnesses or other information where appropriate;
you do not neglect your teaching duties while the dispute is progressing.
The final point is particularly important. Formal disputes can be emotionally draining, and can have an impact on how you behave in the classroom. Try to have a clear dividing line between your conflict and the rest of your life; it is particularly important that you have support - both from your union representative and from your friends and family.