A simple reception situation.
Above the roof install a Winegard HD7696P antenna with No amplifier aimed at about 160 degree magnetic compass direction.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.
Here are some above the roof antenna mounts ,
http://www.ronard.com/909911.html ,
http://www.ronard.com/34424560.html ,
http://www.ronard.com/ychim.html ,
http://www.ronard.com.
Buy the ronard antenna mounts at solidsignal by typing the word ronard in the solidsignal search box.
Here are some places to buy antennas and etc. ,
http://www.solidsignal.com ,
http://www.winegarddirect.com ,
http://www.amazon.com.
For 1 Tv connected use no splitter.
For 2 Tv's connected use a common simple 2 way splitter.
For 3 Tv's connected use a common simple 3 way splitter.
For 4 Tv's connected use a common simple 4 way splitter.
The Tv/s Must Channel Scan for the Digital Broadcast Tv Channels sometimes named the 'Air Channels' or 'Antenna Channels' in the Tv setup menu because the Tv transmissions travel through the air from the transmitting antenna to the receiving antenna.
DO NOT channel scan for cable tv channels.