I always iron both the quilt top and the backing. I draw out all my quilting pattern then I use T.pins to pin down my backing into the carpet taunt Always make sure it is 2-3 inches bigger on all four sides then the quilt top is.
Then put the batting on smooth out any wrinkles then lay quilt top onto the batting. I start in the middle area always with pinning and I pin from middle out on all four sides every 3-4 inches.
I always quilt from the center out to one side then middle to other side out. If you quilt in the ditch the complete quilt you can go back to any area to quilt other designs.
When I'm quilting I have a empty coffee cup setting off to the side and I remove pins as I go along.
Remember it is better to pin to much then not enough.
I'm pinning one tommorrow it usually takes me 3-4 hours to pin a queen size. If your pins get dull use a bar of soap while your pinning rub the tip of the pins across the soap it helps.
They do get alittle dull after awhile.
Enjoy the quilting process have fun