In this tutorial I'm going to show you how to make a simple "aqua button" effect. You need to know how to apply effects to the layer and you need to know how to load a new gradient. This tutorial was made in Photoshop v6 and should work with newest versions just fine.
First make an new image of any size (this tutorial is 150x100 pixels). Add a shape of whatever you want, for this tutorial i choose a rounded square and named the new shape layer "button".
You should have something like this:
Now we need to apply some settigs to the "button" layer.
Double click on the "button" layer until you get the "Layer Style" window.
Now enter the settings shown in the images below.
For the "Gradient Overlay" you need to apply a new Gradient, download the gradient here.
Now you should have something like this:
This is a fairly simply tutorial. Its not a 100% perfect aqua looking button, but it is a simple effect that works and looks very close to the real thing.
But if you got lost somewhere or didn't do it right, you can download the file here.