Transcribe your piano compositions to staff paper, available in music stores, or as a printable download online. Music notation software, available for under $100 as of this writing, works by transcribing the notes you play to sheet music. This is done either through a MIDI keyboard attached to a computer or by inputting the musical notes into the program. Composers who don't wish to buy software can simply write the music onto the staff paper.
Determine what sort of binding to use. In what is called a perfect -- or adhesive -- binding, the left-hand edges of the pages are glued together, and then a piece of heavy paper or cardboard is wrapped around the front, spine and rear of the glued papers. This is not an ideal method for a book of music, because the binding may fail if the book is opened frequently. A sewn binding is more sturdy, but it may be difficult to open the music book to set on the piano's music rack. The best solution for a book that will be used frequently is a binder with rings, so the pages turn easily.
Decorate the binder, and create a title page. Include your name on the binder, and use a decorative technique that reflects your style of music. Add the title to the spine, so that when the binder is on a shelf, you can determine its contents. Put the book's title, your name and the date on the title page. Include a copyright notice, so your music can't be stolen.
Assemble the book. Put a blank page at the beginning and end. These are called the first and last free endpapers. Next, insert the title page, followed by the music. If you have multiple sections in your music book, use binder tab dividers to separate them. Consider adding a few blank pages at the end, in case you need to write notes about any of the compositions.