One interview, then a follow up after background check

I applied online for a position with ResCare. I waited several days and had not heard anything back, so I obtained the phone number of the Director of HR from a friend who had interviewed with ResCare and called him to express my interest. He asked a brief question or two and then forwarded my call to an HR associate. She asked me a few questions about my education and experience and then set up an interview with the department managers for the following week. I had a panel interview with both of the managers that next week. They explained the functions of the job and then began the interview process. They asked some behavioral questions, but mostly questions related to my resume. They were friendly and laid back. They took turns with each person asking a question off of a sheet of paper and recording the answer. I received a job offer two days later via a phone call. I accepted and met with HR the following week for background checks and drug tests. I started the following week.