Once you use good firm chipboard for covers, 3 or 4 book rings will hold it together and be very easy to open to add a new page. In case you're not sure what I mean -
THIS is the type of book ring.
Cover and decorate your chipboard covers, and with something like the Crop-a-dile punch 3 or 4 holes down the spine edge. Some people get an amazing look by tying little ribbon knots round the book rings.