I recevied a request from Ginger Sala:

• For marketing purposes I want to combine 2 separate photos of Roger and me...both are currently on white background. I want to put them together and overlay them on another photo..beach background.

Let's see ......

First choose and open your three photos.
One for Background.  One photo containing the Ms.   One photo containing the Mr.

Start with the prep work:

Take a moment to think about the size and lighting of the Ms. and Mr. images. 

For each image, click View -> Actual pixels.  To do this properly you need to be working the image's original size.

Lighten or darken each image separately so they match. 

Look at the size of each individual, Mr. and Ms..  Resize as necessary so they match.  Pay particular attention to the head sizes.

If you need help lightening, darkening or resizing, just holler.

Now:  Extract each individual.  Here's how to use the Magic Extractor tool.  It's actually quite easy.

Remember to keep all three images open.  Use the move tool   to drag the first individual into the background.  Postion the individual.  Move the seond individual.

Note the layers palette: 

Each image placed on the background becomes a separate layer.  Note that the highlighted layer name in the palette indicates the active layer.  You change the active layer by clicking on the layer name.  When a layer is active, you can edit that layer.  Getting familar with layers might be the most important point of this silly post.  :-)

If you want the individual images to overlap, you can change which image appears on top by clicking Layer -> Arrange .

When you are satisified with the postiioning of all the individuals, click Layer - Flatten Image to merge the layers together

All right -- I have some "fine tuning" to do

Notice I accidentally snipped the top pouf of marilyn's hairdo off. 

This can be easily fixed with the Clone Stamp.   Click the Clone Stamp -- ALT click somewhere in Marilyn's hair -- release the ALT key, then click in around at the top of her head to add the hair back it.

Once I filled in all the missing hair, I used the smudge tool    to blend it in with the existing hair.

I cloned and smudged to get rid of the little stray white artifacts.

You can also use the smudge tool to just slightly soften the edges of the individuals.

Here we go ... (Not perfect by a long shot, but you get the idea!)

More about using the Move tool to create a photo collage here.