Embossing an image is not difficult, but its success relies on careful image selection. A good candidate image will have some texture, but not too much. Images with a large amount of detail may require too much "clean up" to be useful.
If you're trying to emboss the subject of your image, you'll want to remove or at least minimise the background before you do anything else. You can use the Magic Wand tool to select the elements of the photograph you want to remove. Once you've identified all of the areas to be removed, press the delete key.
Everything that was selected with the Magic Wand tool will be replaced with your default background colour. You may have to repeat this step several times to remove all of the unneeded material from your image.
Once your image is clean, save it as a GIF file and place it on a transparent background. Open your image in RGB mode and choose Stylise/Emboss from the Filter menu.
This will transform your image from its colored state to a grayish image. Using the sliders, adjust the depth of the embossing and the angle. You can preserve detail by increasing the opacity of the image.
Save your image. Gray is not always the nicest color in the world, so once your embossed image is saved, you can adjust the color to one that complements your design. To do this, you'll want to select the Enhance/Adjust Color option. Select Colorise and adjust the Hue, Saturation and Lightness sliders to narrow in on the color you want. A background image shouldn't stand out too much, so aim for light colors.