JQuery or Javascript

JQuery or Javascript

Greetings all,

I learnt a little XHTML1.1 strict and CSS2, then got into base level HTML5 and CSS3.
I'm self-taught, and now at the stage of wondering about next moves.
  • What's the relationship between Javascript and JQuery?
  • Is it necessary to learn Javascript before becoming involved with JQuery?
  • Other than this site, what others are recommended as reliable references?
  • What books are recommended purchases for someone starting at ground level?
Thanks for any time and trouble.
Cheers!

Weaver.