A] Faraday's Law says you son't have to jump one first ... just hook 'em up + to + and - to - and you should be OK. Current follows the path of least resistance, and that isn't all that hard.
B] When you are the donor vehicle, you don't have to turn your truck off. This is one of those urban myths, peerpetuated by Chrysler dealers with electronic dash's... the suge used to kill the computer in the speedometer on those ... a $1500 touch.
An easier way to protect your electronics is to leave your truck running (the donor vehicle) while boosting, but with the HEADLIGHTS ON - that will soak up the extra voltage spike when boosting.