If you've never taken one, I highly recommend it. I've pieced some ten quilts, but have never quilted. The class I took was at an lqs (not the same one I had issues with last week).
The instructor talked to us about the best thread-choices for piecing, versus quilting; the differences between cotton, polyester, metallic threads (plus a whole host of other threads); the differences between needles (sharps, metallics, ballpoint) and their thicknesses; batting --- maximum quilt lengths, differences between silk, cotton, blends, bamboo (she gave us samples); cleaning and oiling your machine; choosing a good chair; good posture; helpful tools (including an ironing table if you don't have a drop-in cabinet or a plexiglass extension table).....anyway, you catch my drift. It was just a tremendous amount of extremely useful information.
The class was six-hours long. We did free-motion and straight line-stitching in the afternoon. We experimented with different tensions, stitch lengths, and patterns. The class, with supplies, cost $45. It was the best $45 I've ever spent on a quilting class.
So, again, if you've never taken a class, no matter how 'seasoned' you think you are, I highly recommend taking a 'basic machine quilting' class. I hope that your instructor is as good as ours was, yesterday, and will provide you with as much information. I feel like I'm completely set-up to succeed in making the best choices for my quilts. It's amazing how all of the 'smaller' factors do come into play for the type of quilt you are making, whether it's an heirloom, utility, charity quilt, etc. There are two very important points she did emphasize in class, though:
1) A finished quilt is a usable quilt; so don't sweat the mistakes.
2) Never let anyone tell you that you CAN'T do something. Unless it's a safety issue (eg. don't stick your finger under the needle), the choices you make for your quilt are completely your own. Don't let someone tell you otherwise. It's all about CHOICES.