My company I had a written test, similar to the NREMT. I had a practical skill exam where I had to assess, backboard, and traction splint someone. Then I had two interviews. Some of the questions:
Why do you want to work here?
Where do you see yourself in five years?
Describe a situation where you have worked well in a group?
What is you philosophy on patient care?
Some situations: What would you do if a physican on scene wants you to stop treating and transport the patient right away? What would you do if you suspected your partner of being intoxicated?
That's all I can think of, but I would really research the company if you can. If they make a big deal on their website about agressive CPAP use, or comunity service or the SWAT medics, or whatever, know that. Also try to ID the important people in the company, so if you are getting interviewed by one of them you know. (one of the guys interivewing me writes for JEMS, I recognized his name and was able to bring up an article that he wrote.)
hope that helps