I'm beginning my rose mat by Joan Moshimer and needed some direction. Rugs in Bloom by Jane Halliwell Green is a great resource. It has chapters on flower anatomy, technique, value and color, dyeing, materials, the hooking of specific flowers and leaves, and more. The flowers are divided by flower shape (cups, stars, bells, spikes, rays, trumpets, cones, etc.). This approach is helpful when working out the value and shading. The book comes with a free pattern for a 16" x 20" wall hanging of lilies and stars.
I am, also, reading A Rug Hooker's Garden published by Rug Hooking Magazine. Ten expert rug hookers give instruction on over twenty different flower blossoms. There's brief instruction on designing a floral rug, jar dyeing, and some dye formulas.
Another resource is Shading Flowers: The Complete Guide for Rug Hookers by Jeanne Field. The book has diagrams that are very helpful in explaining the fingering technique, and it has a lot of dyeing information.
I've decided to hook my first rose in a 3 cut with 8 swatches of Maryanne Lincoln's basic red. I'll post a photo later.