Discuss with your clergyman your desire to become a minister so you can get a recommendation to a denomination committee. This committee will eventually sponsor you for the seminary. By going through this process you will receive necessary help, even financially, as well as receive an appointment of a mentor. This process is also vital in determining whether you are really cut for the ministry. Graduation from seminary will lead to your becoming ordained in many denominations.
Master of Divinity Degree
Some organized denominations require a Master of Divinity degree in attention to a Bachelor's Degree from seminary school before becoming fully ordained. Even if a Master's is not required, it is still a good idea to earn one as the coursework provides the best possible foundation for becoming a minister. Just make sure the seminary you attend is accredited by the Association of Theological Schools.
Clinical Pastoral Education
Most official denominations also require theological students to undergo a process known as clinical pastoral education. This process educates potential ordained ministers in the ways of dealing with the actual needs of people rather than just learning about theology in theory and studying scripture. This process is usually quite intense and engages the student with both a supervising minister and the kinds of people to whom they can expect to minister.
Online Ordaining
For those not interested in taking the official process toward becoming ordained, there are multiple web sites that offer the promise to become ordained for little more than the price. Study and human interaction are are eschewed in favor of a quickie route to calling oneself a minister. The legality of this approach is very much in the air so be forewarned before becoming ordained online simply for the tax advantages. As for trying to become a minister in an organized church, do so at your own risk and do not be surprised to find yourself relieved of your ministerial duties.