First thing I do is check the "freshness". Take a single peppercorn and touch you tounge to it (bite one in half first if necessary). You should get a numbing sensation almost the way benzocaine (oragel) feels. Sichuan cuisine is right up there in my top two favorites.
This book is a must, and I plan to dig into it with a couple years of dedication once I satisfy my French and Regional American interests. Afterall, it's the cuisine from the region where these peppercorns come from!
"Land of Plenty"
Amazon.com: Land of Plenty: A Treasury of Authentic Sichuan Cooking: Books: Fuchsia Dunlop
It has a perfect 5-Star rating with 22 votes as well.
Incredibly simple, but addicting dishes using authentic ingredients and techniques. Amazing book.
The noodle dishes, and Mapo Dofu are downright delicious (the only recipes I've tried so far).