I applied through a recruiter. The process took 5 months. I interviewed at US Air Force (Woodbury, NJ) in Sept 2010
Interview
Entered active duty in 1992 and been in ever since. you will be screened on physical and academic qualifications, and will be provided choices of fields based on these metrics and your availability date. Word of advice to those exploring the Air Force as an option: join because you want to be an Airman first...there will be ample opportunities to enter, and change your actual career field if you desire.
I applied in-person. I interviewed at US Air Force
Interview
The interview went great. My then supervisor sat me down and asked questions about where I see the job going i the future. IT was a give an take conversation leading into getting the job.
Meet with a recruiter and they will discuss your options with you. If you qualify they will then take you to take the ASVAB test to see where you would best be suited to work.