Handiquilter has some great videos on their website. Here is what I learned about tension... 1) check the bobbin tension first and every time you put a new bobbin in or start having a tension issue. Place the bobbin in the case, lay it flat in the palm of your hand and pull up on the thread. What you want is for the bobbin to stand up in your hand and thread to come off fairly easily. If the bobbin lifts off your palm it is too tight! If the thread comes off the bobbin without making it stand up, it is too loose! Once you get the bobbin right, then you can sew a sample to check top to bottom tension. Do not be afraid to turn that tension dial! Every thread type/brand will likely require a different setting.
I love quilting on my Sweet 16! The throat space and table space makes a world of difference!