With DirecTV you split the signal with a multiswitch. Good ones include Spaun and Channnel Master. I have a 2x4 multiswitch. This means it takes the two leads coming off the dish and makes them into 4. There is also 2x6 (6 outputs), 2x8 (8 outputs), etc. If you see a multiswitch that starts with 3x that means it has an input for an antenna or cable and will integrate the signal into the DirecTV cable. This is good if you cannnot get locals from DirecTV.

A decent 2nd box costs about $50 and you pay for it once and can buy it anywhere (unlike cable where a box will cost you $400 or a monthly rental fee).