Show/Hide to create splashpage for Wordpress?

I am trying to create a splashscreen for a wordpress site.

The splahpage, is just a gif that plays an animation.

I have managed to use this jquery on a mock up html site and it seems to work:
Meerkat: A jQuery Plugin

I need some help in moving this to a Wordpress site. Where do I put the jquery files?

Where do I put the function? and the HTML?

I am trying to create the effect that the gif loads and plays and then fades away to reveal the wordpress page underneath.

Can anyone help me with this?

Thanks

I think you can add this to the header, you should read this document.

Also you should have an option to add custom HTML/JS but you have to disable code filtering which I think should be enabled by default.