I've been hearing a lot of buzz about SitePoint's JQuery: From Novice to Ninja.

Remy Sharp's - jQuery for Designers

Learning Jquery 1.3 - I've heard it's good

I'm thinking of picking up Novice to Ninja, too. Has anyone here actually read it and can give a firm recommendation or not?

Sitepoint Novice to Ninja - I've heard good things here.
If you're a real newbie, try Javascript: The Missing Manual. It get's you in the basics of JS and then right into JQUERY! It's a great book.

I like jquery enlightenment PDF version. ( only $15 ).