Contact your local USMC recruiter. From there they will assist you in the process of enlisting. Boot camp is 3 months. MCT is 1 month. And training for you Military Occasional Specialty (MOS) will depend on what you’re going to do.
I applied in-person. The process took 3 weeks. I interviewed at US Marine Corps (Kansas City, MO) in Feb 2014
Interview
Take the ASVAB test for job placement. Your score depends on job qualification. A brief discussion is required to ensure you adhere to the policies. The recruiter will assist you in the process until the day you depart for basic training. Trained professionals guide you through the process and ensure that you qualify.
I applied through other source. I interviewed at US Marine Corps
Interview
There was no interview. There were lots of physical exams. Lots of medical exams. Mandatory drug tests as well. Lots of physical fitness tests as well.