How do I connect my Sirius to my satellite ready Pioneer DEH-P3700MP?

I am unsure of your particular model without googling it, but I'll try to answer your question. Read the manual that came with your stereo...since it is satellite ready, it should have a SID# which is about 14 digits long.These numbers are the numbers that are required for your Satellite provider (XM or Sirius) to go through your car stereo with out any equipment. It will come out on the display of your stereo which you can write down and give to the satellite provider. Since your stereo is satellite ready it should have all the functions of a basic satellite...changing the satellite station, etc. For those operations you will need to read the manual. Hope that helps.