How can I apply "glow-tan" on my pictures?

Maybe it's me, but I have no idea what you mean with glow-tan...

The effect I think that you're trying to achieve mimics late afternoon light or gold reflectors. While this is best done while shooting, you can kind of do it in post, but I would probably do it with a warming filter in Photoshop.

In Aperture, try using the Color Brick. Select yellow then use the eyedropper to select the skin tone. Adjust the saturation and luminance sliders until you like what you see. You may also have to adjust the Hue slider depending on the subject's skin tone. You want to add a tint of orange: if it's too yellow, it will look like tungsten light. When you have what you like in the skin tones, you can use Brush Color in/Away to selectively apply the effect. This effect should be very subtle: don't hit the viewer over the head with it.

Be sure your white balance is right before you start.

DLS

PS I had this response finished before I saw the last two posts. That article is hilarious: It says, "Photoshop...can be used by almost anyone with a modicum of computer experience." then gives instructions that require at least an intermediate knowledge of Photoshop to follow.

My suggestion would be to use the Burn Quickbrush and then brush the adjustment in. Or use color adjustment and brush that. For more information on brushes, take a look at the Aperture manual.