There is a short phone interview with an HR associate from Atlanta who goes over minor details like your previous experience, what type of education you have...they speak to the schedule of the site you are applying for as well as the main benefits.
If that goes well, you will get another call to schedule testing. Although the testing requirements seem to change with demands for hiring. Basically look at taking an AON test and Ramsay test, possibly a matching test as well.
If you make it through that phase you will have an in person interview with at least one manager, sometimes two. Assuming everything goes well at this stage you will be required to pass a physical and then a background check.