NCE Computer Group interview questions

I had found a posting with NCE Group on Craigslist.com. I replied to the email provided with a cover letter and my resume. A Rep sent me an email with approx. 7 questions to answer and send back. About two days after I replied to the email, I received an email to come in for an interview. It was to be a three person interview. I showed up, walked into the building and used the phone provided to call the desk. A lady by the name of Rebecca met me at the door and escorted me into an office...two gentlemen followed. They all took turns asking me questions and it almost felt like a cross examination. They were all very polite and very informative. Rebecca had stated they received an abundance of resumes and they have interviews until the next week. She said I would hear from them within a week and stated they won't forget about me. I heard back from them within the hour offering me the position. They sent me an email to print, sign and fax back to authorize the background check and drug screen. The next say I faxed everything back and they emailed me a form for the drug screen to print and take with me to the lab. I have not heard back regarding my schedule or required attire but was told when to report to my first day.