Cut the cardboard into three pieces, one piece for the back cover, one for the front cover, and one to fit the spine of the book. The cover should be no more than 1/2 inch larger then your book's text.
Decide on your fabric to use for the cover. Lay the fabric flat on the floor or table, and place the three pieces of cardboard side by side on top of your fabric. Cut the fabric leaving plenty of extra fabric all the way around your cardboard, two to three inches should be enough. Iron down about a half inch on both ends. Place the cardboard on the wrong side of the fabric. Fold the fabric over the right edge of the back cover, and begin by gluing the fabric to the outer edge of the back cover. Just fold in the flat edge first, leaving the top and bottom for later. Place clothes pins or potato chip bag clips to secure.
Spread a thin layer of glue on the inside of the back cover and carefully stick the fabric to the back cover. With the back cover secure, leave about a fraction of an inch (depending on the thickness of your book) or just enough to allow freedom of movement to open and close the books cover. Glue the binding piece of cardboard to the fabric.
Spread a thin layer of glue on the inside of the back cover and carefully stick the fabric to the back cover. With the back cover secure, leave about a fraction of an inch (depending on the thickness of your book) or just enough to allow freedom of movement to open and close the books cover. Glue the binding piece of cardboard to the fabric.
Once completely dry you will be ready to add your contents. Hold all of the text pages of your book securely, and then add glue to the back edges of the stack of paper. Place the text of your book onto the back binding of the cover, close the book and place clamps on the back binding to hold it all together.
Allow this to dry for about two days. If you try to take it apart before the glue is completely dry, you may have a mess to reconstruct.