Not Zillow, but integrating other API's how to's are available
How to Integrate PayPal API's into FileMaker Solutions | December 9, 2011
MailChimp Integration with FileMaker Pro – Part 1 of 3 | July 10, 2010
However, you'll have much more power and flexibility if you use the Zillow API -- you'll need to use a plugin such as ScriptMaster from 360Works to do this.
Drupal Module for Filemaker
The filemaker module lets you build FileMaker web applications through Drupal.
Thank you for your reply! I will take a look at the links you posted.
Yes, the elance job posting is mine. It has only been about 24 hours since I posted the job but I have not received any quotes. While I am able to pay a little bit of money to get someone else to program the solution, I would also like to know how to complete the integration so that I can make future modifications. I may have to pay someone to at least get me started. I feel that if I can get the first Zillow API query successfully inputted into my FileMaker Pro application, the remainder should be relatively simple. The complex part is finding step-by-step instructions on how to do it! It has been very frustrating trying to find any documentation for something that I know that FileMaker Pro can achieve.