How to knit necks

I want to knit a square neck shirt (I should state that I have not made any type of clothing since I was 17). I can find directions on how to do the body and sleeves, but the neck area has me confounded. Any suggestions on where to look?

It should be similar to making a round/crew neck. You may want to start a little lower, BO more of the middle stitches, and probably not do as many decs along the neck edges.