Sweater know how

i am trying to knit the sweater in the guide post mag.
it seems like you work in all in one piece, but how do you add on the extra sts. for the sleeve?:??

Just cast them on by cable cast on.

Are you referring to the t-shirt type sweater in Knit for Kids? Yes, just cast on either with cable cast on or backward loop. There are videos under basic techniques at the top of the page.

so i add them on the left hand needle with the other stitches