While my 09 B2300 has an Aux input, I did use the following with great results in a previous vehicle:
First create an aux input to your radio:
This is an "IN-LINE" fm transmitter, meaning your radio antenna plugs into it, and then it plugs into your radio. The sound quality is as good as a strong FM radio signal.
Second, make that Aux input a dash mounted 3.5 MM stereo jack.
The FM Transmitter provides you RCA input jacks. This accessory lets you convert those RCA lacks to a dash mounted 3.5mm stereo jack. Just requires drilling one small hole for the jack.
Next you need power for the iPod and a line-out signal for your new Aux input:
This is the Monster Cable Ultra-Low Profile iPod iCharger (AICHG2 IP). It does two things:
1) Provides a line-out to plug into your new AUX input
2) Provides power to the iPod with a neat trick. When power is cut to the Monster Cable Ultra-Low Profile iPod iCharger (AICHG2 IP), it send a pause signal to the iPod. So if you wire it up to only get power when the radio is on, when you stop and turn off the truck the iPod is paused so you can start the music where you left off.
While my 2009 B2300 came with an Aux, I use the Monster Cable Ultra-Low Profile iPod iCharger (AICHG2 IP) to power my 32GB iPod Mini. The iPod is mounted between the radio and the instrument cluster. I just need to run the cables behind the dash as soon as I get a chance.