The things I would do are
1. Don't include jquery.js as we already have jQuery, just include the slider script, it does need to be below the jQuery script so view the source of the rendered page to make sure of that.
2. Instead of using an id on youre div I would use a class like this <div class='jq-slider'>
3. Remove that script from the header where you are trying to wire it up. and try putting something like this at the bottom of your layout.master just before the closing body tag.
Hope it helps. Let me know how it goes I've been thinking about building something in to make it easy to use that slider or some others