I know I mention the Momofuku cookbook to the point where some people might be starting to think I'm David Chang shilling, but I assure you I'm much poorer and a fraction of the cook on my best day.
That said, the book has a whole section on pickling in which watermelon rinds are included as are some favorites like mustard seeds, birds eye (thai) chiles, carrots, and cucumbers. He does various types as well like the quick pickle (3:1 sugar to salt basically), vinegar pickles (noted above), fermented pickles (kimchi - cabbage and my favorite, cucumbers - delicious), and even soy pickles (****akes, though I don't care for mushrooms and can't speak to them).
I highly recommend picking up a copy of
The Momofuku Cookbook as I've found it to be one of my most referenced AND cooked from books.
[/shill]