If vacuum bagging, the taping of the individual sheets together and cutting to shape are the only things that are necessary before the actual core to sheeting bagging. The epoxy resin (laminating) or Gorilla Glue will hold the individual pieces of sheeting down to the foam core (and the edgeas will be percfectly held down - without the need to edge glue the sheets together and this therefore eliminates one sanding step.

The above is shown in Jim Young's video referenced earlier as well as the video from ACP Composites that comes when you get one of their vacuum bagging set-ups.