However you can't truly master jQuery without also developing a thorough understanding on JavaScript. The alternative would be to construct a hodge podge of jQuery plugins and widgets to get things done - and then running into all the limitations, conflicts and outright bugs they will bring with them. [I have borrowed from such sources but have always needed to modify the code]. Much better to be able to write clear straightforward code of your own in JS - taking advantage of jQuery when it is an advantage of course.
Apart from anything else JS is a delight and learning how to use it will develop your programming skills.
So I am now forcing myself to start working on some basic JS tutorials and my friend recommended I pick up this book: jQuery: Novice to Ninja: New Kicks And Tricks.
However, I all the time need to get things done using tools like jQuery, underscore.js, async etc ... These libraries make my work so much easier and I don't necessarily understand the internals of their working.
Things seem to working fine so far and my knowledge of the fundamentals keeps on improving as I work. That works just fine for what I am trying to accomplish.
That said, you don't need to go crazy and go off it cold turkey, you can very much expand your JS knowledge while using jQuery still for day to day AJAXy and DOM manipulation tasks.