I applied through a recruiter. The process took 2 weeks. I interviewed at US Army
Interview
A recruiter will ask for proof of High School graduation or proof of earning a General Education GED. They'd ask if you have ever been convicted of a felony or a criminal domestic violence charge. If past the initial part of screening the recruiter will look up available jobs and try to assist you in picking a job that is aligned with the military test you must take. The job choice is yours in the end; and chosen with a career counsel at the Military Entry Processing (MEPs) center.
I applied through a recruiter. The process took 3 days. I interviewed at US Army (Boise, ID) in Jan 2011
Interview
Walked into the Recruiter's office, took the ASVAB later, signed a contract. Its ridiculously easy. As long as you can read and write, stay within a very very reasonable weight range, and can avoid doing drugs or getting a DUI you'll make it. It can be the easiest job you'll ever have and it's definitely the easiest interview process.