Cast on the correct # of stitches. Then BEFORE you start knitting, put some sort of marker on the left hand needle -- either a plastic ring or a loop of yarn. THEN make sure that you are holding the needle with the "Starting yarn" in your LEFT hand before you begin.
Transfer your marker to the right hand needle and then knit the first row according to the pattern. STOP when you reach your marker. Turn your work around by switching needles, just like with straight needles. Then move your marker and knit the 2nd row according to the pattern.
Continue like this back and forth. I always pretend I'm working with straight needles and need to switch them back and forth from row to row.