The process might depend on "who" interviews the candidate. My personal experience was actually very refreshing and not your "standard interview experience". I spent 2 hours talking very candidly with an owner/manager of the company. He never looked at my resume but preferred to relate questions directly to me and was conversational in sharing the aspects of the job. I believe the interview process relies heavily on "intuition" about the candidate...so preparation would be secondary to the impression one leaves based on personality (e.g. integrity, compassion for people, assertiveness in asking for the sale).