Regarding where to start on the border... What I would do is lay the quilt on a table. Smooth the bottom border. Pin thru the bottom quarter or half inch of the border, keeping the pins parallel with the border. attach the backing to the leaders & roll the quilt onto the front bar. You will find this pretty easy because you pinned the bottom border down first. When the top border is in position, smooth then put a couple pins near the edge. Using your machine run a line of stitches close to the edge. smooth the top border and whatever portion of the side borders are available. Put a few pins in the edge on the top & sides. Now run a line of stitching across the top, removing the pins as you go, then down the 2 sides. Use a long stitch length. Once the edge is stitched down you can start quilting anywhere you want. When you are done with the top border, don't just roll the rest of the quilt up. roll section by section, smoothing and stitching the edges of the side borders as you go. This will keep the tension good across the whole quilt and get you set up for when you turn the quilt. When you get to the bottom, secure the edge removing the pins as you go.