I don't know how freezer lab looks like, but if it is like many rows with boxes, maybe you could start with a calendar example.
calenders are rows of boxes... then you could click a box and show another layout displaying what is inside a rack, etc.
here is a good calendar to start with : http://developer.filemaker.com/solutions/detail/?item=solution.10000000392
You could actually take a digital picture of your freezer, put it on a layout and then overlay it with invisible buttons. Clicking a button can pass a parameter to a script which then displays the desired subset of your data.