About Those Butt-Ugly Dollar-Sign Variables

They're private-scope variables hung on our utility object, $.
Members of the $ object may be treated as global variables within the context of our SEARCH object.
The choice of $ as the object name is immaterial; we could just as easily have used localGlobal, like this: localGlobal.q.
Yes, okay, this is horribly confusing. And it gets worse when you try to read up on it; you'll run into gems like this:
"Having the one-off function call return the class constructor forms a closure that can hold private static members and assign privileged static methods as properties of the returned constructor."
... which has all the semantic meaning of that Dr. Seuss poem, where the tweedle beetles battle in a puddle in a bottle on a noodle-eating poodle.
Dustin Diaz has an article on this: JSON for the Masses, at http://dustindiaz.com/json-for-the-masses, and posted an important comment on the YUIBlog, at http://yuiblog.com/blog/2006/06/01/global-domination, by way of response to Mr. Crockford's Global Domination article, previously mentioned.
My best advice for beginners: read everything you can find on the subject and let it all wash over you. Learn to recognize and exploit patterns in the structure. And practice!