The first thing would be to start with the S-130/190 training program part of the training can be completed through on-line information located at: http://training.nwcg.gov/courses/130190faq.html you will have to find a location to complete the practical part of the training. Usually the organization, State or Federal, that offers the practical part, may have a way for you to be place on a hand crew list within the State. If you are not a State of Federal employee, it may take some time to get this completed. I would suggest you not give up in trying. I started with my first trip in 1994, I was a structural firefighter making the cross to wildland fire, while still being a full-time structural firefighter. My first trip was with a mixed crew of State, Federal, and AD's (Emergency Hire) firefighters. Since that time, I have been on assignments from Florida to California, Minnesota to Texas. If you are in Oklahoma, I would start with the State of Oklahoma, which is in the Southern Area Coordination Center: http://gacc.nifc.gov//sacc/ Watch for training and information through their web site. You might be able to work through US Department of Interior Indian Affairs: http://www.bia.gov/nifc/ which also provides firefighter training and crews during fire season. Once you have a trip or two under your belt, then would be the time to start looking for a position on a Type 1 fire crew or Hot Shot Crew if you wish to proceed with the profession. Hope you have good luck in your endeavor and like I said don't give up if you really want to give if a try..
www.usajobs.gov is about all I can add to Gregs reply... The BLM recruits from here. Good luck and be safe!