If your familiar with File Maker, MySQL should not be too different.
The main difference between the two is that MySQL is a relational Database, whereas file maker is more of a Flat file.
We Offer a free MySQL eCommerce Database that you can use as a starting point:
http://www.webassist.com/community/tutorials/view_tutorial.php?tid=101
and also a Database Getting started guide that should be helpful:
http://www.webassist.com/community/tutorials/view_tutorial.php?tid=104