building new theme, Javascript compatibility

Plugins distributed on ww.wp.xz.cn should be compatible with the jQuery version that comes bundled with WordPress – I would continue to use that jQuery library.

I think you just add this to your Child Theme functions.php file:

wp_enqueue_script( 'jquery' );

There are other scripts that come bundled with WordPress in case you want to use them too: http://codex.ww.wp.xz.cn/Function_Reference/wp_enqueue_script#Default_Scripts_Included_and_Registered_by_WordPress