1. With right side of your work facing you, knit to the position for the bobble. Knit the next stitch but leave it on your left needle. Yarn Over into the same stitch but still leave it on your left needle. Continue working knit one, yarn over into the same stitch until you have the desired number of stitches. Drop the stitch off your left needle after working the last stitch.
2. Turn you work and knit across the bobble stitches only. Knitting only the bobble stitches, work the desired number of rows, turning your work after each row (4 total rows).
3. With the right side of the work facing you, using your left needle, pick up the second stitch of the bobble on your right needle. Pass this stitch over the first stitch and drop it off your needles (casting off). Pick up the "new" second stitch on your right needle. Pass this stitch over the first stitch and drop it off your needles repeating until only one stitch remains. Then continue working to the end of the row.
NOTE: I used the book A to Z of Knitting: The Ultimate Guide of the Beginner to Advanced Knitter in learning these bobbles, but found that the yarn over was more successful than the methods proposed in the book. There are many different ways to make a bobble, but this way worked for me.