Open Photosuite or your scanning software and scan your image. When scanning, make sure the dpi (dots-per-inch) setting is at 150 or less. That is usually all it takes to ensure your image will be small enough to post in the gallery. If scanning a 12x12, you'll need to scan two halves. (To keep things organized, number the scans when you save them.) Edit / rotate image if needed. Save as -fill in name- select file to be saved in and choose Jpeg image from the drop down box.
Open your file where you save your images. Select open with MS Paint or other image editing software. At the tool bars across the top of the screen, select Image and click stretch/skew. I fill in both horizontal and vertical stretch values as 40. This makes your image smaller. If it is still to big and you can't see the whole image on the screen, then repeat the stretch/skew step, filling in 60 or 80 for the values. If it shrinks it too small, just undo that last change and re-do it with a larger number. Remember that the larger the number entered for the value, the less it will shrink it. The smaller the number, the more it will shrink. Ex: shrinking it with values of 50 will shrink it to half the size or 50% of the original size (if you have two halves of a single LO (12 x 12) -- remember what values you select because you must repeat the exact values for the second of the second half in order for them to match and stitch.)
At this point, for a 12x12 LO, I have three windows open. One page is the first half of the scanned LO above. Second page is the second half of the scanned LO, following the same steps as above. Third is a blank or new page opened in MS Paint. In the third window, using the page arrows, open the blank page as big as you can. This gives you more room to stitch your LO together.
Go back to the first window, your first half of the LO. There are little picture tools on the left hand side. At the top there is a dotted-line box called select. Click that tool. Now click and drag from the very top corner of your image to the opposite lower corner, completely framing your image with the box. Right click and choose copy. Open the third window and paste this image on the blank page. Repeat steps with the second half of the LO in the second window. Now you have both halves on your blank page.
(In my MS Paint I can only move the last image I pasted. The first image pasted is stuck where you placed it. Before copying and pasting the second image, make sure you place the first image where you need it. It's all trial and error. If you need to open up a new blank page and try pasting the two images again, that's fine.)
Stitching is fairly easy. Overlap the two images until they meet at the seam. It's ok if you can see the seam. It happens to everyone! Don't forget to SAVE! Now open with Photosuite and crop, edit and save. (make sure it's Jpeg.)