You also have a choice of using double pointed needles for small circular knitting. I would choose them over 2 circs.
But to do with two circs, you need two sets of the same size needle -- the cords can be different lengths. You would put half the stitches on one set and half on the other with the needles that have the stitches on them parallel. Lets say that the left one is red and the right one is blue (for purposes of explaining). And you want to knit the stitches from the red needle. You would use the other end of the red set to knit those. Slide them to the other end of the cable. Then you'll knit the ones on the blue needle with the other end of the blue needle. Sliding the stitches all the way to the other end of the cables and start all over again.
Hope this helps a little but I fear I didn't explain it well