Hold the hook in you right hand and loop the yarn from the ball over your left index finger. Hold the end of the slip knot between the thumb and middle finger of your left hand. With your left index finger, wrap the yarn from back to front around the shaft of the hook. Use the hook to draw the yarn through the loop on the hook: one chain is now made.
Make as many chains as your pattern calls for. Do not count the slip knot or the loop currently on your hook as chain stitches. The resulting row of chains is called the foundation chain. You will build the crocheted fabric off of this foundation. The chain stitch is also used to produce spaces and loops in your fabric.
This technique is courtesy of Lion Brand Learning Center of Knitting and Crochet Information.