easiest with that information is probably a fm transmitter. i have my iPhone connected to my aftermarket head unit through blue-tooth. there are other radios that connect to the front or back of the radio. in my old car i found a fm transmitter that plugged into the back of the radio then ran the wire from that to the headphones port on the iPod which worked perty good on a stock radio but involved pulling the radio and running power and ground wires also. there are many ways to connect you iPod to your radio it just depends on what you have and what you want to do with it.
1999 Ranger XLT 4x4 - Daily Driver
1991 Ranger XLT - Sold
1995 Ranger Splash - Lowrider - Trying to sell