I find it very strange that this doesn't have many reviews.. Sure this isn't really your typical step by step guide on the subject, but if you intend on trying out an endless variety of flies, this is THE one book to own. I scanned through the majority of this and the photography is perfect. It's simply a catalog of flies with the materials needed, but a very good one at that. I've never seen anywhere close to this many patterns throughout ALL of the other 20+ books I currently own. I didn't count, but it claims over 3600!
This isn't cheap, but it's most definitely worth it.