Need help making on-hover pull-down menu

Hi guys,

I want to make a pull-down panel like the one on this website - where it says CONTACT FORM at the top. The only difference is that I want the pull-down to open on hover, instead of on-click, and also bring the content down with it, instead of making a mask for it.

Can someone please point me in the right direction for a decent tutorial please?

Thanks you!