Got my house wired with sockets when it was built. Modem plugged into a phone socket and a switch in the attic (4 storey town house), cables run to sockets in all rooms in the house. PCs plugged into sockets using 1-5m extensions as required. Master phone box is on ground floor. No problems whatsoever.
Videk will sell you cables up to 30m off the shelf and extention cables. Good company, used them many times.