Here is a tutorial for the star book that I posted on here the other day. These instructions make a 4" square book, and a six point star.
Step 1: Cut your cardstock into six pieces at 4" x 8", six pieces at 4" x 6 1/2" and 2 pieces at 3 3/4" square.
Step 2: Fold all the pieces, except the 3 3/4" ones, in half.
Step 3: Decorate the smaller pieces and the the square pieces. If you are using embellishments keep them flat so it will close properly.
Step 4: Stick the edges of the smaller pieces to the edges of the larger pieces so they create this shape.
Step 5: Stick the backs of each piece together making sure to leave a back and front cover.