Here is another tutorial that probably uses items already in your stash. No need to buy anything new. I made this little accordion mini book with regular business sized envelopes.
You can use those return envelopes that come with the junk mail because you will be covering up any lettering, or you can use new ones (like I did because that was all I had. If you're more patient than me, you can wait and save those junk ones).
Start by sealing 5 envelopes and then trim off 1/2" on each end so that the envelope is 8 1/2" long and has 2 open sides.
Then score them in half at 4 1/4".
Fold them in half and crease well. Now, line them up-accordion fashion-open end at the bottom, next one has open ends at the top and so forth.
Where the two sides overlap, is where you are going to adhere them together so that you end up with an accordion. Set aside. Now I cut 2 chipboard pieces to 4 3/4" square for the covers and adhered patterned papers.
Glue one end of the accordion envelopes to one cover and the other end to the other cover. It should look like this.
Now, you will need 10 pieces of patterned paper cut to 4" square to decorate the envelopes. This leaves just a bit of the white still showing as a border. You can distress the squares, or ink the edges at this point and then adhere them to the envelopes. Then you will want to punch out a half circle as such right in the middle of the pocket.
Continue with all 10 pieces. Now it should look like this.
Then I cut out solid colored cardstock to fit each pocket (approximately 4" square) and stapled on a little piece of ribbon so it is easier to pull them out of the pockets.
You can keep it closed a bunch of different ways depending on what look you are going for--attach ribbons to the covers before adhering the envelopes to tie it closed with ribbon, add a large rubber band around it, use a Tim Holtz grungeboard hinge, add a button on the front and tie closed with twine, etc.
There is a lot of room for photos and journaling when finished.