There are several things you can do to prepare your quilt top and backing for an optimal quilting experience.
If your quilt top will have borders, I strongly recommend creating them using pre-measured strips, rather than just cutting a strip, sewing it on, and then trimming off the excess. Using pre-measured strips that are the actual length/width of your pieced blocks will significantly reduce the chance of excess fullness in the borders, which can cause problems when quilting.
Press your quilt top and backing to remove any stubborn creases.
Square up your quilt top and backing.
Make sure your backing fabric and batting is at least 4 inches wider than your quilt top on all sides. (e.g., if your quilt top is 60″x70″, then your backing and batting should be at least 68″x78″)