What’s the best way to prepare for an interview?

Do your homework. Read publically available company and industry information. Ask for bios and/or access information on the people you’ll be interviewing with. Review the job description or position specification and practice responses to anticipated questions. Come with at least 3 questions to ask your interviewer, if they allow the time.

I never know how much to say in response to interview questions?

Follow the “3 Minute Rule” – stop your response after 3 minutes and either ask the interviewer if this is what they were seeking, or allow them to ask another related question. “Yes” and “No” responses are rarely acceptable responses – elaborate.