If it's like what my new home had, it's really easy to do what you want. It came stock with every jack wired for phone, and an extra run of unused CAT5e on the left. I took everything off the included phone splitter, used a standard network cable crimper to add ends to the rest of the wiring, and plopped a 16 port switch inside the box.

On the wall jack side, I bought some plates and inserts, and just rewired them. The inserts work just like a punchdown, where you put the wires in the insert and a plastic tool to push it down.

A friend of mine wired his entire house with lots of CAT6, then bought various modules to pipe audio or video over CAT6 cable. Routing it was accomplished by going to the wiring closet, and using a coupler to join the two jacks together.