Here is what I do to use it:
- create a new image of the size I want the button to be
- apply any affects such as gradients
- play the action
The end result will be an image with a beveled up shape on the left side (normal state) and a beveled down shape on the right side (pressed state). I would have attached it to this post but I didn't see any option for attachments (even though the FAQ says it should have been there)

-- Dave