Here's a great tip for figuring out that perfect jQuery selector.
Open up your browser's console (I use chrome) and try different selectors in the console. The browser will show you what it selects.
Using Google Chrome:
"Inspect element" In the element inspector select the Console tab
You can type commands right into this console. Try a few selectors only and see what you get. If you type $('p') and hit enter it will list out all the p elements. If you enter $('ul.nav li) it will show you if that selector works (returns anything). If the command does not result in a valid selector it will return .