Baste your quilt layers well using your preferred method (i.e., safety pins), leaving no more than the space of your hand between pins. Begin your quilting in the center of the quilt and work outward, being very careful to completely smooth out all layers in each area before beginning to quilt in that area. If using straight line quilting, I highly recommend using a walking foot.

Is there a good way to keep thequiltbacking straight while using a regular home sewing machine

I think the backing is sometimes just as important as the quilt tops. I am forever inquisitive as to what the backings look like whenever I see some beautiful quilts. I wish the magazines would show a corner of the backing in their photos of the quilts.