I have a 10in craftsman table saw with the fence. How would I square up the sides of a 1x6x4ft board? Would i need jig of some kind. Or would using circular with a straight edge be better. Mainly looking for proper technique using a table saw. Thanks.
Unless you already have a straight edge on your board, your fence will just replicate the errors of one edge to the other. What you need is a straight edge jig. It's fairly easy to build. Here's an example from the Wood Magazine.
There's also many videos on YouTube.