Some friends asked me to help lay a brick porch approx. 5' x 7' off the back of their house. What do I need to do to prep the site? I assume I'll need to dig out an area, lay gravel (possibly), then sand (& tamp w/ a tamper), level then lay the bricks/sand in between them? What about a trim/outside edge plastic/rubber/poly piece I think I can get that from Home Depot or Lowes. Any other help is greatly appreciated.