I had some clear-mount cases lying around. I've been wanting to do this for a long time. I thought these might be perfect for my daughter's new teachers, so I got busy.
The cover piece is DSP cut at 7" x 10". I used My Digital Studio to design the "notes" layer.
This is the inside. The pocket on the left is made with 5 1/2" x 6". With 5 1/2" side on top, score 1/4" on each side. With 6" on top, score at 3". Fold the score lines and apply tape on the 1/4" portions. Use a circle punch to create a notch.
Another option, is using the same DSP as the front piece, after you cut the 7" x 10" for the cover, use 1/2 of the bigger left over piece to create the envelope. This piece is 5" x 6". With 5" on top, score 1/4" on each side. With 6" on top, score at 3". With the 7" x 2" piece left over, you can cut it down to 5" x 2" and cover the top of the notepad.
I got the notepads from Office Depot. The size I got is 5" x 8", in a pack of 12. I then took it to the Business Center counter and asked them to cut the pads down an inch. The cutting only cost me $1.25 for the whole pack. You could also get the 4" x 6" notepads and possibly have room left over for a pen, too. Just have to remember to get skinny pens, so they'll fit in the case when closed.