Did you read the "sticky" posts on this page?
http://www.3fatchicks.com/forum/forumdisplay.php?f=163
You can get quite a few ideas from them, and the recipes. I've checked out books from the library about the Med diet and the Sonoma diet (they're similar).
The beauty of this 'diet' is that there are so many staples that could work that it's hard to make a list. It's very diverse. I'd say to get yourself some olive oil if you don't already have it (plant-based oils are used instead of butter), fresh fruits and vegetables (locally grown, if possible), seafood and poultry, dairy products (yogurt and cheese are my favorites). And don't forget the wine!
Here are some links found in the Mediterranean Chicks forum that might get you started:
http://oldwayspt.org/index.php?area=pyramid_med
http://www.mediterraneandiet.gr/
Good luck, and let us know what you buy!