Oh, and just to note, none of the links below are affiliate links.
If you’re used to working with jQuery (or any other library) in some capacity, then this will help shed light on how those particular libraries do what they do.
You’ll also have a much clearer understanding of some of the syntax that other libraries use, and how you can implement similar functionality (such as chaining) in your own work.
Note that this isn’t a reference book – it’s better read cover-to-cover.
Where Do I Start?
Finally, I consider these two books to be the best on the language that I’ve found thus far, but if you’ve got your own suggestions, please link ’em up in the comments.