First, simply cut however many pages you like to be in your book in the desired size, mine are in the size A5 and I have around 30 pages. Next, take the thicker piece of paper and measure it to fit around the front, the keel, back, the other keel, and around half of the cover again. Fold the cover and fit the pages inside, secure with the paper clips. Next take a piece of paper in the same size as the paperback, make a mark for the holes, I fold it in half and again in a half for this one. Secure the paper in with the paper clips. Your next step is to make the holes. What I use is a tool I found in my boyfriends toolbox but you can also use a large nail for this step, it'll do just as good. Just watch out for your fingers. To bind the book together I decided to do a traditional Japanese book binding method, for full instructions on how that is done go here. I highly recommend using a wax of some kind to smear on the string that you will use to bind your book together. That will help the string stay in place and prevent the knots from loosening up. You can buy waxed string in art supply stores, use the same wax as you use on snowboards or even candle wax. Lastly I took a decent amount of string and secured it by the middle hole in the back, threaded it to the front so that it can be wrapped around to close the book securely.
Making books is something I really enjoy doing and if you are interested in more book binding DIY kind of posts we can defiantly arrange something of that kind in the nearest future. Good luck!