I think it is important for an instructor to provide their academic background and work experience but nothing is more important than responding quickly to student questions and concerns. Often times I get an email from a student and I'll acknowledge I received it and then I'll let them know when they can expect a reply from me. I try to answer all questions immediately but there are times that I can't answer their question because I don't have the text book handy or I need to check with someone else. In those cases I think students appreciate knowing I received their request and when they can expect an answer.