Department heads shall be nominated by the mayor based upon merit and after due consideration of qualifications for office. The board of mayor and aldermen shall adopt a procedure for the selection of department heads which shall require a job description for each position, the posting and advertising of any vacancy in appropriate publications and final selection after an interview process has been completed. Qualified candidates shall be interviewed by the mayor or appropriate commission under Section 3.08 of this charter. The mayor may nominate his choice from among such candidates. No department head shall take office until the nomination has been confirmed by a vote of eight (8) aldermen.