Great customer service starts with knowledge! Regardless of the position you hold within your company you should know as much as possible about its processes, the ethics under which it operates and the goals that it hopes to achieve. Whether you work the front desk or are the CEO of the company you should be able to answer more than just basic questions about the company for which you work.
This is a valid point regardless of your industry. If you work in a restaurant you should be aware of each dish on the menu, how it is prepared and if any substitutions can be made. If you work in retail know each item that the store carries and where it can be located- not just the items in your department. If you work in a bank learn about the various products that your organization offers and how they can benefit different consumers. You should know more about the company than your clients do and you should be prepared to answer questions that are outside of your normal scope of work.
It is also imperative that you not make up any answers! If you are asked a question and you are not confident you can answer correctly then let the client know that. They will appreciate the honesty over a false answer that could lead them astray. Also, you will appear more adept and competent if you seek out the person who can provide accurate and complete information.
Being an expert about your company will provide your clients with the confidence that they are dealing with the right organization and the right person!