Use the magic wand to select parts of a photo you want to keep. (It will remove the rest.)

Here are the two steps:
1) Select: Draw on the parts of the image you want to keep. Continue until you’ve selected everything you want to keep.
2) Remove: Click away (or on another tool) to remove the unselected parts of the image.
Tip: You can click the Undo button to restore your original image:

After you remove the background, you can touch-up with the Eraser tool:

For best results with the Magic wand, take photos with a solid, contrasting color in the background.