The best way to learn jQuery is to code while you're at it. Now, I consider myself as a newbie in both Javascript and jQuery but I'm doing some personal projects that I'm going to release soon when I received my own server. The projects are small and jQuery related.
I develop plugins, animation plugins that animate the body of the page. I develop a slideshow for images. But you know what, I think jQuery really makes thing damn simple. Especially for animation.
I'm afraid that I'm gonna lose my knowledge in Javascript once I program in jQuery for too long.
I also recommend you to emulate the flash designs in Javascript. If you go to Gamespot.com, you'll see that their designs are flash. Try to do something similar using jQuery/Javascript.
Hey, and you got your own style of learning. I learn by reading the book. Once I finished reading the book I'll go sit down on my computer and program everything I learned. If I forgot something, I'll just open the book and find the reference. I found it the best way to learn programming. But you might have different style of learning. Maybe you prefer reading and programming at the same time. Or checking out the source code and learning from there.
Do some blogging in your portfolio. Detail how you created the jQuery plugins. Contribute to jQuery. Make people use your plugin. Share some love.
