My side shelf (which you store milk in) is broken. How do I find out what Whirlpool refrigerator model I have as it's an integrated into a cabinet and so I can't see the number. I need to order a replacement shelf

Typicaly it is found on a sticker on the back! In your case I suggest taking the broken shelf to a local appliance dealer and they will be able to match it with a replacment for you.

The model and serial should be on a sticker on the inside of the refrigerator (most models
have it on the left side as you are looking in the refrigerator but some have it on the
right side). Hope this helps.