What documentation should you have if you want to represent somebody else in court, so that the judge/prosecutor cannot say anythign to you about not being allowed to represent?

could i just verbally state that i'm here to represent?

a written statement signed?

is there a proper form?

You cannot represent someone else if you are being paid or receiving any sort of consideration. The government enacted legistaion last year in the Law Society Act. If you are just helping a family member or friend for free you still can, but the court can stop you at any point and time if you haven't a clue what you're doing or disrupting the proceeding.

When you get to court just advice the court who you are and what you're doing. The rest of it it up to the court.

Appearance by defendant

50. (1) A defendant may appear and act personally or by representative. R.S.O. 1990, c. P.33, s. 50 (1); 2006, c. 21, Sched. C, s. 131 (7).

Appearance by corporation

(2) A defendant that is a corporation shall appear and act by representative. R.S.O. 1990, c. P.33, s. 50 (2); 2006, c. 21, Sched. C, s. 131 (7).

Exclusion of representatives

(3) The court may bar any person, other than a person who is licensed under the Law Society Act, from appearing as a representative if the court finds that the person is not competent properly to represent or advise the person for whom he or she appears, or does not understand and comply with the duties and responsibilities of a representative.

lawmen is quoting the Provincial Offences Act above. You should also know that the exemption to the licensing requirement is under the Law Society Act, By-law #4, Part 5, Section 30, sub 5 (pg 24). Print this and have it in your back pocket in case you get challenged in court about defending your friend.