My scanner software is HP Image Zone. I do everything right there.
step 1. Scan the page that fits on the glass. Try to get as much of the top and bottom as you can.
Step 2. Rotate the page so it gets the other half. This half will be upside down.
Step 3. If your scanning software allows it, rotate the image twice until it is right side up, then scan. If not, you can turn it around later.
Step 4. While I have my scanned half pages in the work area of the program, I open Projects.
Step 5. I open Panorama.
Step 6. I take the left side of the page and slide it into the first part of the panorama.Then I take the right side and slide it into panorama. They have to be in the right order.
Step 6. Click create panorama. If necessary, click "autocrop".
Step 7. I "save as" the panorama to a file in "my pictures" called scrapbook pages. This makes it easier to find to upload to scrapbook.com. Then I clear those pages out of the project and move the next two halves.
I repeat as many times as I have scrapbook pages scanned. I do all my scanning first then create the panoramas.