Quality of custom slider
You never use slider.selector, so what's the point?
jQuery instances should be "cached", otherwise you are creating new jQuery object each time you call $() function.
This code permits only one slider per page. What if you need more? Will you copy-paste the whole thing?
This is not configurable at all. You have to change the objects source, just to change the way animation works.
jQuery is not really necessary here. You actually need it only for animations, which is not jQuery's strong point.
Slider object ends up in global scope.