If you plan on having say wall mounted flat screen tv's, the best advice I could give would be to run some ducting or sizeable conduit between the tv position and where you plan to have your entertainment systmes (dvd, sky box etc.). Then you could pull through what every cables you would then need.
In terms of surround sound, alot of systems don't necessarily need rear projecting speakers........but if you plan on having these, then plan for the rear speaker positions and either chase out the concrete floor to cater for some ducting/conduit/cable for same. There are other options, like hiding cables behind skirting boards or through stud walls if this is an option