Here's a good biodiesel resource: www[dot]biodieselnow[dot]com

Definitely be prepared to change the fuel filter. Biodiesel is a solvent and will cause the dirty buildup from dino diesel to break up and clog the filter. Also, if the fuel lines are rubber, replace them with viton. Biodiesel will dissovle rubber (not very fast, but it will happen) resulting in leaks and eventually failed lines.

Are you planning to make the biodiesel, or buy it?