Well, couldn't find the thread I was looking for. Maybe someone else out there remembers it? I believe the guy who posted was a school teacher or something similar and had a program where he helped kids in school build a bow. He used boards and had some real good pictures showing grain orientation, what to look for, what to avoid, layout etc.
I searched "board bow" and a bunch of topics come up but not the one I'm looking for. Also searched "build along, building, board, and making" but didn't find it.
If you read some of the board bow posts, it should get you what you need to know but I really liked this one particular post.