You can look at Demo of a Small Project on the Tips page, to see a piece from caston to bind off which shows how you progress from the cast on to the first row. When you're at the end of the row and turn to start the next one, move your yarn out a little to the side, then to the back. Too often new knitters have the yarn up over the top of the needle to the back which pulls up the first stitch and makes it look like 2 sts. That's a great way to add extra stitches when you don't want to...
sue- knitting heretic