Thought I would share my categories also: Redwork/Embroidery; Patchwork Quilts; History; Specialty Books; Borders, Tips, & Techniques; Hawaiian; Miniature; Paper Piecing; Sampler Quilts; Crazy Quilts; Quilting and Designs; Needlepoint; Beading; Knitting; Crochet.
I made dividers from old manilla folders and keep the books in horizontal file drawers. This is what works for me.