1. Buy 2pcs of cardboards (in the size of booklet, or you can trim)
2. Buy papers (in the in the size and format of booklet)
**If you want to make booklet in ring blinding format (what you said have plastic rings on left hand side, you better have a special holes puncher. If not, you can use ordinary single hole puncher to make holes one by one. It will be time consuming.
3. If you use the special holes puncher, you can buy the rings (it will be in one piece) from many stationery store. That special holes puncher allow you to insert it. If you use the single hole puncher, you can also use that one piece ring, but takes time and quite difficult to insert it with the paper.
***Just wonder why you have to make it buy yourself?