Just run standard cat6 phone wire to all the places you want either a phone or network outlet. Make sure the plans include separate cat6 runs to a central wiring "closet" that will be in the same place where the phone company wires in your phone service. If you do that, you can do whatever you want to later. Standard cat6 includes 4 twisted pairs of copper wire. You need one pair for a phone line and one pair for a network connection. Cat6 is a little more expensive than cat5 or cat5e.

Once you have the wire runs, you can buy faceplates with any combination of RJ11 and RJ45 outlets on them and wire them up yourselves. It's not hard to do.

You can go nuts with this stuff and buy all sorts of connection blocks for the wiring closet to make it easier. But you don't need all that to get started. The independent runs of cat6 are the only important thing when building.

-David