It is rarely needed to connect a DVD player directly to a DISH Network (or any satellite TV) receiver box. In fact, it will only make sense if the player is also a DVD recorder. The only other possible advantage will be to avoid switching the TV to its video channel to play DVDs. It may not even be possible to directly link the DISH Network box to your DVD player. It will require input ports on the DISH Network box or DVD player that may not be available on either.
Look over all the connection ports in the back of your DISH Network receiver box. An older model box may have RCA input ports available. Connect the DVD player's output to these input ports with RCA cables and skip ahead to Step 6. If there are no such ports available, move on to Step 2.
Check the connections on the DVD player. It needs to have input ports that will match up with any output ports on the DISH Network box (meaning RCA, S-video or RF coaxial). If it's a simple DVD player and not a recorder, it may not have input ports at all and you'll need to connect it to the TV directly.
Connect the DISH Network receiver's output to the DVD player's input. Use a cable that will connect any compatible ports that are available--coaxial, RCA or S-video. If you can, use the cable that currently connects the satellite box to the TV by disconnecting it at the TV end and connecting it to the DVD input port.
If your satellite system comes with a digital video recorder, use the previous step to connect the DVD's input to the DVR's output. The DVR should already be connected to the DISH Network receiver box; leave this connection alone.
Link the DVD player to the TV set by connecting a DVD output port to a compatible input port on the TV. If the TV was connected to the satellite by a coaxial cable, this option may not be available on the DVD player. RCA cables may be your best option.
Turn on the satellite box, TV set and DVD player (make sure they are all plugged in). Insert a DVD into the player. If all the appropriate connections are made, the satellite TV signal should broadcast on the TV set and the DVD video should appear when the disc is played.