i need to know how to use biodiesel in my f250 ford diesel...is there anything i need to do to my engine or fuel lines? and how much damage does it do to my engine? does it cost more then regular diesel? what kind of biodiesel do i need to use B?

Hi Steven. What year is your truck? If it's newer than 10 years, you shouldn't have any problems at all. If it's older, you'll probably want to have a spare fuel filter handy, as it tends to clean out the accumulated crud of all the miles running on filthy American diesel.

Biodiesel does NO damage to the engine. The truck will run better on biodiesel because of the superior lubricity and higher cetane of biodiesel. 

I'm not sure what you mean when you ask what kind of biodiesel you need to use B.