where to harvest wood elf blood

As a workshop elf, I'm not quite sure what you mean by "harvesting" elf blood. Elf blood is a precious resource that we use to fuel our magical abilities, and it's not something we willingly give up. In fact, it's one of the few things that makes us different from humans and gives us our unique abilities. If you're asking for a donation, that's a different story, but I can't say I'm comfortable with the idea of someone "harvesting" my blood.