The Ortho Problem Solver book is best I believe. 1,100+ pages with colored pic of disease, bugs, fungus etc. When I bought mine in 1994, it cost me $250. Now its around $200 depending who you buy it from.
"The most up-to-date solutions, from non-chemical to recommended chemical controls, for more than 3000 plant problems and North American home pests."
Stihl Kombi System
028 Super, 066 Chainsaws, PP 800 Pole Saw
F-150, F-350 Trucks
Ariens Rear Tine Tiller
5x12, 6x12, 6x14, 8x16, 7x18, 6x22
Asus Transformer Infinity TY700 Tablet
If you think it's expensive to hire a professional to do the job, wait until you hire an amateur.