Directions on how far from the guides to the blades are often confusing... Many say a few thousandths of an inch...the thickness of a folded dollar bill (or for high end bandsaws, a folded hundred dollar bill). My problem is that a sheet of copy paper is about .004 (four thousandths), a dollar bill is about .006, and a business card is at least .010. So I don't understand people who say "a few thousandths" and then suggest a folded dollar bill (12 is more than a few).
I adjust my saw so that the side bearings are "nervous" - they twich a little as if they are trying to turn when the saw is not cutting, but definitely do not turn continuously. If the blade vibrates enough that the bearings have to be pulled back significantly to avoid turning, you need more tension. The thrust bearing should not touch the blade except when cutting, but as close as possible without touching (dare I say "a few thousandths"?)
If you have a carbide blade, do not file the back of the blade - they are already ground, and that voids the warranty.