Big challenge you've taken on! Good for you! It's always good to stretch yourself...
I would lay out all the rows and then stitch one by one - take a picture of the actual fabrics as they are laid out, - it will be very helpful. Hopefully you have room to lay it out?
I am making this quilt:
Over & Down Under Quilt Pattern by All Through the Night - Craft Warehouse
and it is very important to keep on track. So far I have five rows sewn and pieced to each other, but I still spend a lot of time checking each piece to make sure it's the right one....