how do i hook up three tv's for direct tv.

DirecTV requires that you have a separate box for each TV. You could run a coax line from one box and split it to multiple TVs, but you will degrade your picture and sound quality to each set. Also, whatever channel that one box is on, all of your TVs will be on.

Your best bet would be to call your DirecTV installer and have them run the appropriate lines from your dish to provide a signal to your additional TVs.