Fading in a (timed out) div

Fading in a (timed out) div

Hi there, I'm fairly new to using jQuery so this question could be pretty lame. I'm looking voor the right syntax to fade in a div. So far I only found syntaxes that deal with button actions but I just want to fade in the div after a few seconds. How do I set that up? Switch off visibility with css and then? Tia.