Some recommend cutting your fabric in half, but I don't like to do that, because the designs are not the same on each side. Pick a long table or the floor. If your mat isn't long enough, just slide it up under the fabric for the second half.
Just re-read the matching and cutting instructions until you are comfortable with them, then keep the book open as you do each step.
You can always PM k3n or myself or anyone else who has done the OBW, and we will be happy to help you. You CAN do this.