Managemylife.com is a great place to find the answers to just about anything, especially on appliances. I have attached two links below from this web page for your reveiw until your expert can respond. Both have great maintenance tips that I hope will assist you.
I see that James R has given you a few links to look over that has tips for cleaning the refrigerator. The second link has the information for cleaning the refrigerator. I recommend following those instructions.
Please let me know if you need further assistance on the refrigerator.