Thanks for the lovely comments everybody :) It's fun to make the quilted album cover, and i actually did document the process, so here's what i did!
1. measure up the fabric with the book that you want to cover
2. sew together 2 different fabrics (or actually as many as you want!) to create the size - iron flat
3. seam together all four sides, with additional quilting details onto the face of the fabric if so desired.
4. measure and cut up 2 side panels for the slots
5. bind and seam all the sides
Voila! A quilted book cover :)