easiest way to find out... take it to a sewing machine repair shop - they can clean and tune-up your machine (you should do this about every year or so) and they will GLADLY show you how to thread the machine, change needles, etc.. (or you can try to...
call a Pfaff dealer in your area and see if you can order the handbook. you could also try googling Pfaff and maybe you could get it from their web site.
The prewound bobbins you describe are specifically used for machine embroidery and not for regular sewing or quilting. You are better off buying a quality brand of thread (e.g. Gutterman or Mettler) and winding your own if you don't want to buy the s...