Photoshop Elements 7 - How do I align/center a layer?

More on centering...

These may not apply in your case but you might want to know for future recerence:

1. When dragging a layer to another picture, holding Shift centers the copy.

2. If a selection is to be copied/pasted into the same picture, deselecting before the paste will center the new layer.

You can also use the grid to center objects by setting Edit>Preferences>Grid as below.

Then with the move tool selected, show bounding box checked, objects should snap to the grid.

Enable the grid by View>Grid.

If you just want to center the image (layer) in the document:

1. select>all

2. select the move tool

3. in the tool options bar use the align buttons: vertical centers and horizontal centers.

pse 7 doesn't have guides.

Are you adding objects to a blank layer? If so bring up the ruler then drag and drop guides to your center and any additional points. You can also set so that objects automatically snap to the guide lines.

If you want to align visually similar images on top of each other, there is no auto-align like in CS5. The only work around is to lower the opacity of the top layer and then use the move tool to align by eye.