Logo Hover effect

The jQuery would be:

jQuery("#logo img").hover(
 function($) {
  $(this).fadeTo("slow", 0.33);
 },
 function($) {
  $(this).fadeTo("slow", 1);
 }
);

See https://codex.www.ads-software.com/Using_Javascript
and
https://codex.www.ads-software.com/Function_Reference/wp_enqueue_script
You’d need to enqueue it.

Where do I add that jQuery code to?

Contact your theme’s vendors. We have no access to commercial themes so we can’t tell you that.

You can do this with CSS. Add

#logo a:hover img {
     opacity: 0.3;
}

If you want smoother animation, you can use CSS transitions.

Hey I’ve added that to my css in my header, and nothing changed ??

I tried to edit your CSS live in FireBug and it works. Maybe you are doing it wrong. Try to edit this rule to the theme’s custom.css file.

Okay great I got it to work. What code would I have to add to it to make it slide nice and easy?