http://www.youtube.com/watch?v=Q1mRhcquZTM
This is FABULOUS about tension on any long arm machine. I do not have a bobbin winder so I use Bottomline pre wound bobbins. I use mainly Connecting Threads Poly longarm quilting thread (forget the name) on the top as it is really cheap.
I was using serger thread on top and having too much breakage. It is just not strong enough.