I have a book called "All in one quilters reference tool" written by Harriet Hargrave, Sharyn Craig, Ales Anderson, and Liz Aneloski. i use this reference all of the time for everything..it has easy to follow charts, tables, and illustrations for yardage requirements, cutting instructions, setting secrets,choosing supplies, piecing techniques, number conversions and the list goes on. I highly recommend it as a quick reference for just about everyone. It is put out by C&T publishing for $16.95..that is the price on mine which admittedly is a few years old. It does have a table for diagonal measurements for squares amd lists them for sq. from 1.5 inches -12.5. If you want to pm me and let me know the sq. size you are interested in i would be glad to look it up for you.