Need help with a collar

[jens2kids]

Hi everyone,

I am making a baby sweater and I want to add a sailor collar to it. I want to knit it right to the sweater neck instead of knitting separately and sewing it on, and I know that there must be a way to do it using short rows. Can anyone give me a hint on exactly I might go about this? Do I pick up all the stitches all the way around right away? I want the lower edge to be square and of course the upper edge is round, so I just don't know how far to knit before I turn and then how often to turn. I hope this makes sense and I thank anyone who can help if this is even at all possible!
Jenny