The free video on Knitting Help has a advanced techniques that discuss knitting cables
Basically a four stitch cable - move two stitches to a cable needle knit the next two then knit the two stitches off the cable needle.
if you have stitches 1, 2, 3, 4 your would move stitches 1 & 2 to a cable needle knit stitches 3 & 4 and then knit stitches 1 & 2 off the cable needle. After the cable the stitches would be in 3, 4, 1, 2 order.
The twist come from how you hold the two stitches that you move to the cable needle. If you let the cable needle hand in front of what you are knitting the cable twists one way, if the cable needle is in back then the cable twists in the other direction.
Cable needle in front and the cable twists right over left, in back and it twist left over right,