One fabulous reference book I use all the time is: All-in-one Quilter's Reference Tool by Harriet Hargrave, Sharyn Craig, Alex Anderson and Liz Aneloski. Amazon has it for $11.38 here:
https://www.amazon.com/All-One-Quilt...e+tool+updated It has a wealth of information to bed sizes, adding sashing, changing to on-point and sizing setting triangles to name just a few. Well worth it IMHO