You can make these journals any size--when I laid the white paper on the scrapbook paper it fit perfectly (you want that slight overhang on the edges since that is the cover of the journal), so I only had to make one cut at the bottom. Note--you could leave the extra at the bottom if you want a pocket in your journal. Just fold it up and sew or staple the edges of the journal to enclose it. Also, this 'full size' journal will only work if you can sew it. You can of course make smaller ones and staple the pages in, as long as you make a size that the stapler can reach in the middle. OR, you can make these larger ones without a machine if you punch holes with a hammer and an awl (I have also done that) and hand sew with some twine, that's cool too.
I didn't make a pocket, so I cut off the excess. Save it! Makes great bookmarks or you can make itty bitty books. I love miniatures, so I'm inclined to make some dollhouse books. Then I could skip the machine, use one staple, and voila! So, you don't need a paper cutter, scissors will work fine.
Now take your paper. I used 8 sheets--you don't want so many that you can't sew or staple them all. Fold each one individually if you want a crisp, clean look. And with the paper--this is also a great way to recycle used paper--I have used papers from the children that only have printing on one side and made journals with them.
Now unfold and stack them all together.
Center them on the cover, leaving space all around. If you're sewing, you may need a denim needle. Use a basting stitch, if you use a tighter stitch it will tear the paper (ask me how I know!).