Generally the aim of resawing a piece of wood s to divide in neatly in half. One thing you have to account for is the kerf of the saw. If you place a line dead center, one side will end up thinner than the other. For this reason you can offset the line from the center by the width of your kerf (this is a measurement you will be able to eyeball with some ease after converting a couple hundred yards of wood into sawdust).
It occurs to me that I should have taken some photos of that layout process in case some are unfamiliar with finding the center of a board with a cutting gauge (I will post that another day).
What I wanted to point out was now that you have off centered your line you have to remember which side to stay on. During a resaw you are constantly flipping your work over so it’s easy to get confused. Too keep things straight, I make a long pencil mark on one side of the line (waste for me, but pick a system and stick to it).
Also, here is a picture of a fairly decent set up for resawing using the overhand grip at the bench. Use a shorter batten than I did though as it will help you to avoid bonking your saw into it as you start the cut. You could even forget the batten and just drive a screw into your bench at a depth that the head would keep the kerf open (I have not tried this yet…but I am going to).
-- Make furniture that lasts as long as the tree - Ryan