You can get the bobbins on EBAY for less than the previous post. I think I just paid about $1 each for them.
I probably downloaded the same booklet that you did, since I just got my White Family Rotary from a relative a couple of months ago. I had a hard time figuring out how to get the bobbin threaded but figured out there is a notch on the part that points out that you have to catch the thread through. Then it will work properly. If you have the correct bobbin and need a picture of how to thread the bobbin case, I will try to figure out how to do that, just let me know.