I applied in-person. I interviewed at US Marine Corps
Interview
I honesty can't remember all the steps verbatim, it was like seven years ago lol. I know they had screening questions, asked what you expected to get out of the Corps, what MOS you're interested in (no guarantee you'll get it), and other things... Just gotta be willing to take what you can get--if you're serious about enlisting.
I applied in-person. I interviewed at US Marine Corps (Washington, DC)
Interview
It was a very easy but a lot of paperwork. Interview consisted of medical check, mental health check, and a drug test. There were multiple tests that had to be taken on a computer and a very long background check.
This was a tough interview process and the screening was rigorous. It will take a long time. I recommend getting started early. This is a long term commitment. You need to be ready for it.
I have to do this for some reason to get access to the GD's website. Interview process, walked into the recruiting office and said "sign me up". Recruiter was a friendly guy, said "Ok!".