Requirements:

Academy Student: None

To become Genin: Must pass academy test with at least a 75% [depends on the village], Must be level 2, must have trained at least three additional skills

To become Chuunin: Must have ran at least 3 missions, Must be level 10, or given permission by your squad leader to partake in the exams, Know at least 6 jutsu

To become Jounin: Given permission by the kage, tested by a ranking jounin, know at least 10 jutsu (non-academy), Must have ran at least 10 missions, Must be level 30 or above. Don the proper attire of a Jounin.

To become ANBU: Given the permission of the Kage, must know Kanashibari no Jutsu, must be competent in nin-, gen- and taijutsu, must be level 35 or above. Know at least 15 jutsu.

To become Hunter-Nin: Must be level 40 or above, have at least 40 in Knowledge (Anatomy), know at least 16 jutsu

To become Kage: Get chosen by village council, or beat the Kage in a duel.

Bonuses:

Academy Student: Allowed to go on E-Rank missions.

Genin: Given a squad, allowed to go on missions from up to C Rank.

Chuunin: Allowed to lead missions if there is no jounin present, given the proper chuunin attire. Allowed to teach in the academy. Allowed to go on missions up to B Rank.

Jounin: Allowed to lead missions and go on missions up to A/S Rank, allowed to teach a squad.

Anbu: Allowed to go on top-secret missions.

Hunter-nin: A Hunter nin disposal kit, given permission to travel around the continent to hunt down missing-nin (must ask Kage first).

Kage: Runs the village.