For traditional blocks -
My two go-to books are Ginny Beyer's, "The Quilter's Album of Patchwork Patterns: 4050 Pieced Blocks for Quilters" and Maggie Malone's, "5,500 Quilt Block Designs". I like the way that they're separated into 4-patch, 9-patch, etc. and they're where I go when I'm looking for inspiration for new quilts. Both are a bit beyond the very basic but offer endless inspiration.