As WildBill said, run Ethernet to all your rooms and to all potential future connectivity spots. All PC and entertainment locations for sure. One connection is enough as an Ethernet switch can be used to share the connection to AV receivers, DVRs, Roku, TV, etc. I would also run Ethernet to your refrigerator, furnace, telephone panel, electrical panel, thermostats, etc. Many off these things are already or going to going to go on line. Don't forget 7.1 surround sound wiring and even plan for 9.2 (whatever that might be) for as as soon as you sheetrock the walls they will release it.
I know a lot of stuff is wireless but nothing yet competes with the reliability, quality, and security of real wire.